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CLASSIFICATION:
GEOGRAPHICAL DISTRIBUTION
CRUSTACEA:
OF THE
we : a ; [—~ eae THE REPORT ON CRUSTACEA he | j
( UNITED STATES EXPLORING EXPEDITION, UNDER . Let a
CAPTAIN CHARLES WILKES, U. 8. N.,
DURING THE YEARS 1838-1842.
BY
JAMES D. DANA, -A.WG
MEMBER OF THE SOC. CHS. NAT. CUR. OF MOSCOW; THE SOC. PHILOMATHIQUE OF PARIS; THE - QEOLOGICAL SOCIETY OF LONDON; THE AMERICAN ACADEMY OF ARTS AND SCIENCES AT BOSTON; THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, ETC.
PHILADELPHIA: PRIN TED BY COC SHERMAN
ON THE
CLASSIFICATION
AND
GEOGRAPHICAL DISTRIBUTION
CRUSTACEA:
FROM D
ca
THE REPORT ON CRUSTACEHA
OF THE
UNITED STATES EXPLORING EXPEDITION, UNDER CAPTAIN CHARLES WILKES, U. 8. N.,
DURING THE YEARS 1888-1842.
BY
JAMES D. DANA, A.M.,
MEMBER OF THE SOC. CHS. NAT. CUR. OF MOSCOW; THE SOC. PHILOMATHIQUE OF PARIS; THE GROLOGICAL SOCIETY OF LONDON; THE AMERICAN ACADEMY OF ARTS AND SCIENCES AT BOSTON; THE ACADEMY OF NATURAL SCIENCES OF PHILADELPHIA, ETC.
PHILADBLPHIA: PRINTED BY C. SHERMAN. 1853.
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Ma 4 ne Bir Sn ore a aii
A REVIEW
OF THE. CLASSIFICATION. OF CRUSTACHA, WITH REFERENCE TO CERTAIN. PRINCIPLES OF CLASSIFICATION.
Tue class Crustacea exhibits a clearness of outline in its types, and a display of relations, transitions, and distinctions, among its several groups, exceeding any other department of the animal kingdom. This fact arises from the very great range in structure occupied by the species. The limits in size exceed those of any other class, exclu- sive of the Radiata; the length varying from nearly two feet to a small fraction of a line, the largest exceeding the smallest lineally more than a thousand-fold- In the structure of the limbs, the diversity is most surprising, for even the jaws of one division may be the only legs of another; the number of pairs of legs may vary from fifty to one, or none. The antenne may be either simple organs of sense or organs of locomotion and prehension ; and the joints of the body may be widely various in number and form. In the branchial and the internal. systems of structure, the variety is equally remarkable; for there may be large branchiz, or none; a heart, or “dne; a system of distinct arterial vessels, or none; a pair. of large liver glands, or but rudiments of them; a series of ganglions‘in the nervous cord, or but one ganglion for the whole body.
Taking even a single natural group, the Decapods ;—the abdomen may be very small, without appendages, and flexed beneath the broad cephalothorax out of view, or it may be far the larger part of the body, and furnished with several pairs of large natatory appendages ;
1396 CRUSTACEA
the inner antennz may be very small, and retractile into fissures fitted to receive them, or they may be very long organs, constantly thrown forward of the head; and descending but a single step, we come to species of Decapoda without proper branchis, some having the abdo- ~ minal legs furnished with branchial appendages, and others with no abdominal members at all.
When we consider, that these diversities occur in a class that may not embrace in all over ten thousand species (not half of which are now known), we then comprehend the wide diversity in the distinc- tions that exist. The series of species followed through, gives us an enlarged view of those distinctive characteristics upon which the limits and relations of groups depend. The network of affiliations, it is true, is like that in other departments; but it is more magnified to the view.
Moreover, the distinctions are obviously distinctions of rank. There is no ambiguity as to which is the higher or superior group, as among Insecta. The variations are manifestly variations in grade, and we may readily trace out the several steps of gradation, as we descend from the highest Brachyura to the lowest Lernea. And while we so readily distinguish these gradations, we as plainly see that they are not steps of progress followed by nature in the production of species ; but, simply successive levels (grades of types), upon which species have been multiplied.
We, therefore, may consider the class Crustacea as especially well adapted for instruction in some of the higher principles of classifica- tion in Zoology;. and, if we mistake not, laws may be educed which have not hitherto taken form in science. These have already been partially alluded to in the previous pages of this volume. But we here bring together the facts in a connected view, in order to state the principles more definitely, and exhibit the full extent of their bearing. We leave out, however, a large part of the details, which may be found elsewhere in this Report.
The fundamental idea, which we shall find at the basis of the various distinctions of structure among the species is, the higher cen- tralization of the superior grades, and the less concentrated central forces of the inferior,—a principle which has been applied to the animal kingdom in some of its larger subdivisions, but which has not been followed out into all the details of structure exemplified among Crus- tacea.
CLASSIFICATION OF CRUSTACEA. 1397
This centralization is literally a cephalization of the forces. In the
higher groups, the larger part of the whole structure is centred in the
head, and contributes to head functions, that is, the functions of the
~ senses and those of the mouth. As we descend, the head loses one
part after another, and with every loss of this kind, there is a step
down in rank. This centralization may be looked for in the nervous
cords; but the facts are less intelligibly studied there, than in the
members, the production and position of which measure the condition of
the forces :—just as we can better measure the forces of a galvanic
battery by the work done, than by the size or external appearance of the plates which constitute it.
- In the Crustacea type, there are normally twenty-one segments, and
correspondingly twenty-one pairs of members, as laid down by Milne
Edwards, the last seven of which pertain to the abdomen, and the
first fourteen to the cephalothorax. Now, we may gather from an
examination of the crab, or Macroural Decapod, acknowledged to be. first in rank, what condition of the, system is connected with the
highest centralization in Crustacea.
In these highest species, nine segments and nine pairs of appendages out of the fourteen cephalothoracic, belong to the senses ahd mouth, and only five pairs are for locomotion. Of these nine, three are organs of senses, six are the mandibles and maxilla. Moreover, these organs are clustered into the smallest possible space, so that the six pairs of mouth organs hardly occupy more room than the first pair of legs. The organs are all small, the antenns exceedingly short, the maxille small lamellar organs sparingly jointed. The vegetative powers of growth have had but little play. The inner antenne are rather large as regards the basal joint, which is devoted to one of the senses, but the rest is nearly rudimentary, and the whole is snugly boxed away, to be extruded at the will of the animal. The exterior maxilla (or outer maxillipeds) cover exactly the other pairs, and shut closely down over the mouth, like a well-fitting operculum to the buccal area.
We hence learn, that the condition of highest centralization in Crustacea, is where the cephalic part embraces the largest portion of the normal structure of the cephalothorax, and the whole is con- tracted within the smallest compass, with the least vegetative growth or elongation of the parts. The forces are concentrated in the more perfectly developed senses and the higher functions of the animal—
not in giving size to the organs of the senses, but acuteness to the 350
St iT RS: Pager er
SS re se a
1398 CRUSTACEA
sensorial function. The perfection of the senses is evinced by the small antennes; for we infer therefrom, not only that the organ is exclusively an organ of sense, but also, that the delicacy of the sense itself is such, as not to require a long-jointed appendage to aid the function. |
This cephalization of the animal is farther observed in the structure of the rest of the thorax and the abdomen. The abdomen, in the first place, is reduced to its minimum size. Vegetative elongation 1s here cut short, as in the anterior part of the animal; and the sphere
-of growth has a narrow limit, owing to the very intensity of its con- centration; and we find that the limit widens as the intensity dimi- nishes.
Again: the central power is indicated by the fact, that the first pair of legs is the strong pair; being properly hands, they contribute espe- cially to the higher functions, that is, the support of the living animal, through their strength and powers of prehension, and not like the following, to locomotion. Thus, as we pass from the centre, the organs are of more and more humble function.
This centre, as we have observed in another place, 1s properly between the second antenne and mandibles. The second antenne and the rudimentary mouth, are among the first parts that appear in the embryo. If we look at it as a centre of force or of growth, we remark that the radii on opposite sides of this centre, before and behind, are very unequal, the latter being six or eight times as long as the former,
a __a relation which is the inverse of the functional importance of the et parts pertaining to each. | Our idea of the condition of highest centralization is thus drawn q from a study of the species. | ; The most perfect state of it is seen in the Maia group, in which the pases of the antennz and eyes are crowded into the narrowest possible compass, and the mouth organs are well compacted within the buccal area, and the legs and whole system have the highest completeness. The form of the body of a Maia is a somewhat flattened ovoid, nar- rowest in front; and the middle point between the mouth and the second antenne, which we call the potential centre of the animal, is situated near the front, say about half an inch from the front outline (excluding the beak), supposing the cephalothorax three inches long. We may call the part anterior to this centre, A; the part posterior, B; and the length of the former, measured on the axis, a; of the latter, 6. These parts may be viewed, as regards development, as
a teeta art eee a eB "
CLASSIFICATION OF CRUSTACEA. 1399
potentially equal; and yet the anterior, A, is six times shorter and as much narrower and lower than the following. It would not, there- fore, be far out of the way to say, in mathematical language, that the functional importance of the two parts varies inversely as the cubic contents of the parts. We pass now to the degradations from this, the highest type. These degradations are seen—
First, in a widening of the space between the antennz.
Second, in a slight enlargement of the outer maxillipeds, so that they do not fit snugly over the buccal area.
Third, in an elongation of the antennee.
These are all evidences of a slight relaxing of the concentrating element. The first, marks the transition of the Maia group to the Parthenopide, and thence to the Cancridew. The second, carries the grade a step lower, to species of the old genus Cancer, also to the swimming crabs and the Corystoids; and the third, marks off the Corystoids as the lowest of the true Brachyura.
While there are such marks of degradation exhibited through the growth or elongation of parts, there is also a mark, equally significant, sn the obsolescence of the posterior thoracic legs, a peculiarity of many Grapsoids. In the Maioids, the species are well balanced; the type is perfect in its development: the sustaining of the central functions allows of the full and complete growth of all the other parts. But the diminution of force may not only be attended with a loosening of the cephalic hold on the remoter of the cephalic organs, but also, in a failure in the production of the posterior organs of the body, or those on the outer limits of the system: and this is what happens in many Grapsoids. The swimming form of the legs in Lupa and allied species
is a similar mark of inferiority. Besides the above evidences of degradation, there are still others in
the Brachyural structure, which act conjointly with the preceding, producing lower grades of species. They are,all marks of a relaxa- tion of the centralization.
Fourth. An enlargement or widening of the sternum and abdomen.
Fifth. The abdomen becoming somewhat relaxed from the venter instead of remaining close-appressed to it.
Sixth. The vulvee becoming more remote from one another, being situated in the bases of the third pair of legs, instead of the sternum.
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CRUSTACEA.
1400
Seventh. The inner antennee losing their fossettes, and being con- stantly exsert.
Eighth. The branchize being more than nine in number on either side.
The first of these peculiarities distinguishes many of the Grapsoids, as well as lower species. The second is observed in the Corystoids, and is an additional mark of their inferior grade. The third occurs in Dromia and allied. The fourth, in Latreillia. The fifth, m Dromia. Dromia and Latreillia have the posterior legs abbreviated,
BE and in Dromia, this evidence of degradation is still stronger, in that af | the fourth as well as fifth pair is short and dorsal. 5 | The last three characteristics, above mentioned, mark a transition g : towards the Macroural type, and the genera of this kind belong with the Anomoura. This transition is seen further in—
| Ninth. The eyes being without fossettes.
: Tenth. The second pair of antennse becoming exterior to the eyes. Eleventh. The outer maxillipeds more enlarged and subpediform. ia Twelfth. The abdomen more lax and furnished with a pair of caudal
( | appendages. s Thirteenth. The abdomen more elongated, and hardly inflexed. |
These several changes exhibit a continuation of the process of re- laxation in the central forces. There is thereby an enlargement of the antenne, and their more remote position at the anterior extremity of the animal; and also, an enlargement of the posterior or abdominal parts of the animal, and a development of appendages in the posterior direction. ‘These marks of degradation, excepting the thirteenth, are found in the Hippa and Porcellana groups, and the thirteenth in the Paguridea. At the same time that these Macroural characteristics appear, the body becomes elongated. The species all bear a stamp of imperfection in the abbreviated posterior legs, as explained above, as well as in the other points alluded to. The subordination of the nine . anterior annuli to cephalic functions, which is so striking in the Maioids, | . has become less and less complete, and the organs less perfect; more- ai over, the habits of the animals are more sluggish, and they are less fitted for self-preservation. The large Dromia picks up a waste shell, and by means of its hind legs, lifts it over its body for protection, and the Pagurus finds shelter in the water-worn univalves of a coast.
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CLASSIFICATION OF CRUSTACEA. 1401
The degradation pointed out, is hence, not merely a variation in the position and size of certain organs, but an actual deterioration: in rank and intelligence.
Other minor points exhibiting difference of grade, might be men- tioned: but they have already been subjects of remark. We state here only one—the character of the fingers of the large hands. In the higher species, these fingers are pointed; in a grade below, in some groups, they have a spoon-like extremity. This excavate form is often more perfect in young individuals than in adults, which is one evidence that it is in fact proof of inferiority. By this mark we learn that the Chilorodine are of lower grade than the Xanthine; the Paguri, than the Bernhardi; the Mithraade, than the Maiade, etc.
Let us pass now to the Macroura. In the typical Macroural species, the antenne, instead of being minute, with the inner retractile, are long exsert organs, and the outer have a large plate as an appendage at base; the eyes are without sockets; the outer maxillipeds are pedi- form, and do not closely cover the other mouth organs; the abdomen is often longer than the rest of the body, and has its six regular pairs of appendages. All these points show a still further relaxing of the centralization or cephalization of the species. There is an elongation of the parts anterior to the mouth, and also of those posterior, and this elongation of the two extremities is approximately proportional to the relative dimensions of the corresponding parts in the Brachyura. If we were to draw out an ovoid with the relative length and breadth of a Macroural cephalothorax, and place its focus so as to correspond with the position of the posterior margin of the epistome, in a manner like that proposed for the Maia among Brachyura, the ovoid would be very narrow, and the focus or centre proportionally farther from
the front than in the Brachyura. In following down the degradation of the Brachyura to the Ano-
moura, we have found the posterior legs becoming abbreviated, and the whole structure in its aspect imperfect. But, in the typical Ma- croura, there is nothing of this seeming imperfection. The legs are all fully formed; the animals are exceedingly quick in their motion, instead of being sluggish; and every organ is apparently in its most perfect state for the uses of the system to which it is tributary. We should, therefore, understand, that the process of degradation, alluded to above, is not one actually passed through in the system of creation; 351 |
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1402 CRUSTACEA.
for by its progress we should never reach the Macroural structure; nor, in the reverse order, should we from the Macroural reach the Brachyural structure. In the remarks above, we speak only of the comparative actual conditions of the species as regards centralization. The Macroura and Brachyura belong to subordinate, yet correlated types of structure, each perfect in itself, and admitting of wide modi- fications, and having its own system of degradations. We add a few words on these degradations among the Macroura. We have seen that, in the Brachyura, the powerful prehensile legs are those of the first pair, these acting for the collection of food, and so contributing to the mouth. In the Macroura, there are species of high rank that have the anterior legs strong-handed, like the Macroura. There are
- others, in which the second or third pair is the strong-handed pair;
others having all the legs weak appendages, with only rudimentary hands or none. The several marks of degradation are as follows :—
First. The outer maxillipeds pediform.
Second. The maxillipeds next anterior pediform.
Third. Second pair of legs cheliform and stouter than the first.
Fourth. The third pair of legs cheliform and stouter than either of the preceding.
Thus as we descend, we find one and even two pairs of mouth ap- pendages beginning to pass from the mouth series to the foot series, and the cephalic portion is thus losing its appendages and high centralized character. Moreover, the power belonging to the first pair of legs in the higher species is transferred to the second pair of legs, as in the Paleemons; or, to the third pair, as in the Penzidsx; indicating a further decrease of that centralization so remarkable in the Brachyura. Still lower among the species, as in the Sergestida, all the legs are weak, and the posterior pair may be short or obsolete,—the same deterioration that occurs in the lower Brachyura.
As we descend farther, there is an increased obsolescence of organs, and every step is one of marked imperfection as well as degradation.
Fifth. The branchiz become external and small. Sixth. The branchise become wholly wanting, or part of the abdo- minal appendages. Seventh. The last two pairs of thoracic legs become obsolete. Kighth. The abdominal appendages become obsolete.
CLASSIFICATION OF CRUSTACEA 1403
Ninth. The eyes and antenne have separate segments, and the abdomen is very long and large.
The fifth point of degradation is seen in the Huphauside ; the sixth, in the Myside and other Anomobranchiates; the seventh is found in several genera of the same group; the eighth in certain Myside. The Anomobranchiates are thus degraded Macroura. There is not merely a relaxing of the centralization; but the forces are so weakened as not to succeed in finishing out the members in the system of struc- ture to which they pertain. The species consequently are not modi- fications upon the level of the Macroural type, nor upon a distinct level or distinct type; but simply imperfect developments of the Macroural structure below the true level of that type. They bear nearly the same relation to the Macroura, that the Anomoura bear to the Brachyura. The ninth step is seen in the Squilloidea, whose relaxation of system and elongation in the cephalic part, as well as abdomen are remarkable.
The continuation of the line of degradation represented in the Ano- moura, is not to be found, as we have remarked, among the typical Macroura. But the structure of the Paguri may be traced into the aberrant Macroura, called Thalassinidea; and thence, both in the abdomen, the legs, and the branchiz, we observe a transition to the Squilloids, one division of the Anomobranchiates. If then, we were to trace out the lines of ‘affinity in the species, it would be from the Mysis group to the typical Macroura, and from the Squilla group to the Thalassinidea, as elsewhere explained. From the latter, the lines lead mainly to the Anomoura and higher species.
In our review, thus far, we recognise one only of the primary types of structure among Crustacea. This primary type is characterized by having nine normal annuli or segments devoted to the senses and
mouth, that is, to the cephalic portion of the body. It includes two, or, we perhaps may say, three secondary types. ‘he first of these secondary types is the Brachyural; it has the antenne small, the inner pair in fossettes, the abdomen without appendages. In the other type (or other two, if so considered), the antennz are elongated, and both pairs free, the abdomen is elongated, and furnished with a series of appendages. This, the second type, is the Macroural; or, if we assume that it embraces two distinct types (a second and third), the two correspond to the typical Macroura and the Thalassinidea.
Se eT aaa
CRUSTACEA.
1404
Each secondary type embraces types of more subordinate character, which it is unnecessary here to dwell upon. :
There is a tendency in the lowest species to a transfer of the two posterior mouth appendages to the foot series, so as to leave but seven cephalic annuli; but it is only a modification of the primary type, as the species have every mark of being degraded or imperfect forms, and are not examples of a new type.
In this primary type, the species vary in ‘ii from half an inch to twenty inches. Two inches may be set down as the average length and breadth for the Brachyura; while three inches is the average jonath of the Macroura, the average breadth being half an inch or less.
The second primary type among Crustacea is as well defined in its limits, and as distinct in its characters as the first. Instead of having nine annuli devoted to the senses and mouth, there are but seven, the mouth, including a pair of mandibles, two pairs of maxille, and one of maxillipeds. The number is permanent and characteristic. There are, consequently, seven pairs of legs in these species, instead of five, the Decapod number; and the species have been appropriately styled the Tetradecapoda. Instead of exhibiting any appearance of imper- fection, or any obsolescent organs, like those lower Macroura that show a transition to a fourteen-footed structure, the organs are all ’ complete, and the whole structure is perfect in symmetry and unique in character. They have not a Macroural characteristic. ‘The eyes are not pedicellate; there is no carapax, but a body divided into as many segments as there are legs (whence our name Chor istopoda) ; the antenne, legs, and whole internal structure are distinct in type. The branchiee are simple sacs, either thoracic or abdominal.
We have, therefore, in the Tetradecapods an expression of that structure of body, and that size, which belongs to a system, in which but seven annuli or segments are concentrated in the cephalic portion of the structure. The structure is far inferior to the Decapodan. The size rarely exceeds two inches, though in extreme cases three to four inches; and probably half an inch is the average length. The» contrast between the first and second of the primary types, is therefore as distinct in the average size of their structures, as in their sane grade or rank.
Superior rank among the Tetradecapods may be distinguished by some of the same points as in the Decapods. The short antenne,
CLASSIFICATION OF CRUSTACEA. 1405
short compact bodies, and abbreviated abdomen of the Isopods, are proofs of their superiority of grade. The abdominal appendages are simply branchial, and in the higher species are naked or non-ciliated lamella. The transitions to a lower grade are seen in the elongation of these abdominal lamellee, their becoming ciliated, and the abdomen being also more elongated and flexible; then in the abdominal lamella becoming elongated natatory appendages, and the abdomen taking a length usually not less than that of the thorax, as in the Amphipods, in which the branchize are appendages to the thoracic legs. And while this elongation goes on posteriorly, there is also anteriorly an enlargement of the antennz, which in the Amphipoda are usually long organs. There are thus two secondary types of structure among the Tetradecapods, as among the Decapods; a transition group be- tween, analogous to the Anomoura, partakes of some of the characters of both types, without being a distinct type itself. These are our Anisopoda. The species graduate from the Isopod degree of perfec- tion to the Bopyri, the lowest of the Tetradecapods. ‘There is thus another analogy between this group and the Anomoura.
The Trilobita probably belong with the second type, rather than the third. Yet they show an aberrant character in two important points. First, the segments of the body multiplied much beyond the normal number, as in the Phyllopoda among the Entomostraca; and Agassiz has remarked upon this as evidence of that larval analog which characterizes in many cases the earlier forms of animal life. In the second place, the size of the body far transcends the ordinary Isopodan limit. This might be considered a mark of superiority; but it is more probably the reverse. It is an enlargement beyond the normal and most effective size, due to the same principle of vegetative growth, which accords with the inordinate multiplication of segments
in the body.*
The third primary type (the Entomostracan) includes a much wider variety of structure than either of the preceding, and is less persistent
* Prof. Guyot very happily names the three great periods of geological history—usu- ally denominated the Paleozoic, Secondary, and Tertiary, or, by Agassiz, the age of Fishes, that of Reptiles, and that of Mammals,—the Vegetative, the Motorial, and the Sensorial epochs ;—the first, being the period characterized prominently by vegeta- tive growth in animal life; the second, by the increased development of the muscular system, as exemplified by the enormous reptiles of the epoch; the third, by the develop- ment of the higher functions of the brain, exhibited in the appearance of mammals.
302
1406 CRUSTACEA.
in its characteristics. It is, however, more remote in habit from the Tetradecapods, than from the lowest Decapods, and is properly a dis- tinct group. Unlike the Decapods and Tetradecapods, there are nor- mally but siz annuli devoted to the senses and mouth in the highest of the species, and but five in others, the mouth including a pair of mandibles, and either one or two pairs of maxilla (or maxillipeds). This is an abrupt step below the Tetradecapods. We exclude from these mouth organs the prehensile legs, called maxillipeds by some authors, as they are not more entitled to the name than the prehen- sile legs in Tanais, and many other Tetradecapods. There is an exception to the general principle in a few species. A genus of Cyp- roids has three pairs of maxille; but this may be viewed as an example of the variations which the type admits of, rather than as an essential feature of it,—possibly a result of the process of obsolescence which marks a low grade, as in the Mysidx, whose abdomen by losing its appendages, approximates in this respect to the Brachyural struc- ture, though, in fact, far enough remote.
The species of the Entomostracan type show their inferiority to either of the preceding in the absence of a series of abdominal appendages, and also in having the appendages of the eighth, ninth, tenth, and eleventh normal rings, when present, natatory in form.
The range of size is very great,—and this is a mark of their low grade, for in this respect they approach the Radiata, whose limits of size are remarkably wide. Nearly all of the species, and those which, by their activity, show that they possess the typical structure in its highest perfection, are minute, not averaging over a line in length, or perhaps more nearly three-fourths of a line.
Taking this as the true expression of the mean normal size of the type, the three primary types will vary in this respect as 24 (two inches) : 6: 1.
The size in this third type, reaches its maximum in the Limuli; and these are unwieldy species, whose very habits show that vegeta- tive growth has given them a body beyond the successful control of its weak system, that is, a larger frame than it has power to wield with convenience or defend, for it is at the mercy even of the waves upon a beach.
This type has its highest representatives among the Cyclopoids, which remind us of the Mysis group of the higher Crustacea. In these, the cephalic part includes six out of the fourteen cephalotho-
CLASSIFICATION OF CRUSTACEA, 1407
racic annuli. Inthe Daphnioids and the Caligoids, they include only fwe. Tn Limulus, only the first fowr can properly be counted as of the cephalic series. In many other Entomostraca, the mouth organs are nearly as perfect legs as in Limulus, and the species, although evidently of a low grade, cannot properly be removed from the group Limulus has its nearest ally in Apus, although this genus has the mouth organs of a Daphnia. The lowest species of the type are the Lerneoids.
A fourth primary type includes the Cirripeds. It is of the same rank as regards cephalization as the Entomostraca; yet, it has so many peculiarities of structure, that it should be regarded as a distinct type, rather than a subordinate division of the third type.
The mean size of the species of this group is much greater than the same among the higher Entomostraca. But if we regard the young in its active Cypris state, and compare it with the correspond- ing condition of species of Cyproids, we shall discover that the species have, in fact, an abnormal growth; a growth which takes place at the expense of the powers of motion or action in the individuals. The body, when it commences a sedentary life, increases in magnitude far beyond the Cypris or Daphnia size ; and there is a corresponding loss of power. The same force will not move a heavy structure, that is sufficient for the tiny model; and when the model is enlarged without a corresponding increase in the seat of power, sluggish motion is the necessary consequence. Thus it is with the Meduse. Individuals of the minuter species, or the larger species, when in the young state, are gifted with active powers of motion; the structure conforms to the forces within: but as the species enlarge, they become slow in movement, or lose almost every attribute of life. The same principle is illustrated again in the Bopyri. The male is a small active animal, related to Jeera and Tanais. The female, of sedentary habits, becomes grossly enlarged and corpulent, so as to exceed by twenty-fold lineally | the length of the male, and nearly ten thousand times its bulk. It is manifest, that the nervous system, or motive power of the female, is absolutely no greater than that of the male; and consequently, the capabilities of locomotion will be ten thousand times less, or the female will move but a ten-thousandth of an inch at the most, while the male is moving one inch, a fact with regard to them, as any one is aware of who has seen the incapability of the female to make any.
ca
1408 CRUSTACEA.
progress by locomotion. This then, is an example beyond dispute, of a system overgrown through the vegetative process, so as to be too much for the motive energies within. The Lerneoids afford a similar illustration of this principle.
For the same reason, therefore, as in the Bopyri, the Meduse, the Lerneoids, and the Limuli, we cannot compare the actual mean size of the adult Cirripeds with those of the other primary types. We should rather infer the mean normal size for such a comparison, from the size of the young before it becomes sedentary, or from that of free males, if such exist. Such males are announced by Darwin, as actu- ally occurring in some species. Moreover, they are very minute, varying from a line to half a line or less in length. This, therefore, is some reason for taking as the mean normal size, the same as given for the Entomostraca.
A fifth primary type includes the Rotator1a. In these animalcular species, the mouth includes a pair of mandibles and often a rudimen- tary pair of maxille; and consequently, the cephalic portion may contain the same number of annuli as in the Daphnia group, with which group many of them have near relations. They have usually an articulated abdomen, furcate at extremity, like the Cyclopoids. The grand point of inferiority to the Entomostraca, evincing the more infinitesimal character of the system of life within, is the absence of all thoracic appendages or legs. The organs of locomotion are simply ciliz arranged about the head; and it is quite probable that two sets (or more) of them correspond to the second pair of antennze, as these are organs of prehension and motion in many Entomostraca. In Cal- lidina, there are two sets, some distance from the extremity of the head, which may have this relation; and the two sets in the true Rotifers may also be of this character. In others, the corresponding parts are actually somewhat elongated.
The species vary in size from a line to a sixtieth of a line. Pro-
-bably one-ninth of a line is the average size.
The actual relation of the Rotatoria to the Entomostraca (which view the author sustained in his Report on Zoophytes (1845) ), can hardly be doubted by those who have the requisite knowledge of the lower Crustacea for comparison. The structure of the body, the jointing and form of the abdomen, when it exists, the mandibles, and alimentary system, the eyes when present,—all are Crustacean; and
CLASSIFICATION OF CRUSTACEA. 1409
a slight transformation of some Entomostraca—an obliteration of the legs and substitution of locomotive cilie—would almost turn them into Rotatoria.
In the classification which has been developed, we have made out five primary types of structure among Crustacea. A grand distinction has been shown to consist in the different degrees of cephalization of the normal Crustacean structure. The consecration of nine annul, out of the fourteen cephalothoracic, to the senses and mouth, distin- guishes the highest type; of seven, the second type; of six or five, the third and fourth; of five or four, the fifth. In connexion with other distinctions in these types, we find that they correspond to structures of different size, the size being directly related to the grade. ‘T’hese particulars may be tabulated as follows :—
Typical number . Mean normal length, in of cephalic an- twelfths of inches or nuli. lines.
Type I. Popopuruatmia ) Subtype I. meh! 9 24 (and breadth, 24). or DECAPODA, i II. Macroura, es: (and breadth, 6).
Type Il. TeTRADECAPODA, . : bas 6 Type II. Enromostraca, ; : : 6-5 1 Type IV. Crrpieepia, : : , . 6-5 1 Type V. Roraroria, ‘ : ; : 5-4 4
The first type is alone in having true thoracic branchie, and pedi- cellate eyes.
The second type has branchial sac-like appendages, either abdo- minal or thoracic, and sessile eyes.
The third type has generally no branchiz, the surface of some part or all of the body serving for aeration. A few species, however, are furnished with special organs for this function. This is, however, no mark of superiority in such species, for they occur even in the Limuli, among the lowest of the Entomostraca. The necessity of them in this case arises from the abnormal size of the species, both the mark and occasion of its inferiority; for the system is thus too large for the mode of surface aeration, found among ordinary Entomostraca; moreover, the shell, which so large an animal possesses and requires for the attachment of its muscles and its movements, is thick and firm, and this is inconsistent with aeration by the exterior surface of the body. The same remarks apply to the liver glands, which are
very small or wanting in the small species. 853
1410 CRUSTACEA.
The third and fourth types show their inferiority to the second, by the absence of a series of abdominal appendages; and the fifth a lower state still, in the absence of both thoracic and abdominal legs. The more degraded Macroura (certain Myside) show a transition in this obsolescence of abdominal organs to the third type.
Some of the conclusions from these facts are the following.
I. Each type corresponds to a certain system of force, more or less centralized in the organism, and is an expression of that force,—the higher degree being such as is fitted for the higher structures deve- loped, the lower such as is fitted for structures of inferior grade and size. In other words, the life-system is of different orders for the dif- ferent types, and the structures formed exhibit the extent of their spheres of action, being such as are adapted to use the force most effectively, in accordance with the end of the species.
II. In a given type, as the first, for example, the same system may be of different dimensions, adapted to structures of different sizes. But the size in either direction for structures of efficient action is limited. To pass these limits, a life-system of another order is re- quired. The Macroura, as they diminish in size, finally pass this limit, and the organisms (Myside, for example) are no longer perfect in their members; an obsolescence of some parts begins to take place, and species of this small size are actually complete only when pro- vided with the structure of a Tetradecapod.
_ The extreme size of structure admitting of the highest efficien activity is generally three to six times lineally the average or mean typical size. Of these gigantic species, three or four times longer than the mean type, there are examples among the Brachyura and Macroura, which have all the highest attributes of the species. There are also Amphipoda and Isopoda three inches in length, with full vigorous powers. Among Entomostraca, the Calanide, apparently the highest group, include species that are three lines. long, or three times the length of the mean type.
III. But the limit of efficient activity may be passed; and when so it is attended with a loss of active powers. The structure, as in the female Bopyrus and Lernzoids, and the Cirripeds, outgrows vegeta- tively the proper sphere of action of the system of force within. This result is especially found in sedentary species, as we have exemplified in our remarks on the Cirripeds.
CLASSIFICATION OF CRUSTACEA. 1411
IV. Size is, therefore, an important element in the system of ani- mal structures. As size diminishes, in all departments of animal life, the structure changes. To the human structure there is a limit; to the quadruped also, beyond which the structure is an impossibility; and so seems the case among Crustacea. The Decapod, as the size diminishes, reaches the lowest limit; and then, to continue the range of size in species, another structure, the Tetradecapodan, is instituted ; and as this last has also its limit, the Entomostracan is introduced to continue the gradation ; and, as these end, the Rotatoria begin. Thus Crustacea are made to embrace species, from a length of nearly two feet (or two hundred and fifty lines) to that of a one-hundred-and-fiftieth of aline. These several types of structure among Crustacea do not eraduate, as regards size, directly from one to another, but they consti- tute overlapping lines, as has been sufficiently shown.
V. In the opposite extreme of organic beings, the vegetable king- dom, the same principle is illustrated. Plants may be so minute as to have free motion and activity, as in animals. The spores of certain Ales are known to have powers of locomotion, and some so-called Infusoria, are now admitted to belong to the vegetable kingdom. These are examples of locomotive plants. Now, ordinary plants, like Cirripeds, are examples of sedentary species, that have outgrown the limits of activity. The life-system of a plant, is in fact sufficient in power to give locomotion only to the minute plant-individuals alluded to; and infusorial species of plants retain it, as long as they live. But when, as in the Alge, vegetative erowth proceeds in the enlarge- ment of the minute infusorial spore, it immediately outgrows its activity, and becomes a sedentary plant. In most other plants, the seed have never the minute size which admits of motion.
The mean size of the Entomostracan type was stated to be one line ; of the Rotatorial type, one-sixth of a line; and we may add, that the mean size of the plant type understanding by this, as in other cases, the mean size admitting of the highest activity—if deduced from the size of plant-infusoria, would be about one-sixtieth of a line.
We observe, that the smallest size of the perfect Macroura (first type) is very nearly the mean size as to length of the animals of the second type. So also, the smallest size of the perfect animal of the second type (Tetradecapoda) is very nearly the mean size of the most perfect animals of the third type; and the smallest size of the perfect animal of the third type is nearly the largest size in the fifth type.
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1412 CRUS TAORA.
In order to compare allied animals of different sizes, it should be noted, that while there is some foundation for the conclusion, that under certain limitations, size is a mark of grade, rapidity of move- ment or action should also be considered; and the more proper com- parison would be between multiples of size and activity. This deduc- tion, is, however, true only in the most general sense, and rather between species of allied groups than those of different types. We may occasionally find something like an exemplification of the law among bipeds, ludicrous though the idea may be.
VI. We observe with regard to the passage in Crustacea to inferior grades under a given type, that there are two methods by which it takes place.
1. A diminution of centralization, leading to an enlargement of the circumference or sphere of growth at the expense of concentration, as in the elongation of the antenns and a transfer of the maxillipeds to the foot series, the elongation of the abdomen and abdominal appen- dages, etc.
2. A diminution of force as compared with the size of the structure, leading to an abbreviation or obsolescence of some circumferential organs, as the posterior thoracic legs or anterior antenn, or the abdo- minal appendages (where such appendages exist in the secondary type embracing the species). These circumstances, moreover, are indepen- dent of a degradation of intelligence, by an extension of the sphere of growth beyond the proper limits of the sphere of activity.
VII. A classification by grades, analogous to that deduced for Crus- tacea, may no doubt be laid out for other classes of animals. But the particular facts in the class under consideration, are not to be forced upon other classes. Thus, while inferiority among Crustacea is con- nected with a diminished number of annuli cephalically absorbed (for the senses and mouth), it by no means follows, that the Insecta, which agree in the number of cephalic annuli with the lower Crustacea, are allied to them in rank, or inferior to the higher species. On the contrary, as the Insecta pertain to a distinct division, being aerial instead of aqueous animals, they can be studied and judged of, only on principles deduced from comparison among insects themselves. They are not subject to Crustacean laws, although they must exem- plify beyond doubt, the fundamental idea at the basis of those laws.
The views which have been explained, lead us to a modification, in some points, of the classification of Crustacea, adopted in the early
CLASSIFICATION OF CRUSTACEA. 1413
part of this Report, and followed out through the subsequent pages. The question, whether the eyes are pedicellate or not, upon which the names Podophthalmia and Edriophthalmia are based, proves to be one of secondary importance. And although still available in distin- guishing almost infallibly the species of the first type, it is far from rendering it necessary or natural to embrace together under a common division the species that have sessile eyes (so-called Edriophthalmia), as done by most writers on this subject.
The term Decapoda, in view of these principles, has a higher signi- fication than has been suspected, since by expressing the number of feet, it implies the number of cephalic annuli characterizing the species. It would not be employing it inconveniently, therefore, if it were extended to embrace all the Podophthalmia, or all species of the first type, including the Mysis and Squilla groups.
For a like reason, the term Zetradecapoda has a high significance, as applied to the species of the second type. ‘The position of the Tri-- lobita still remains in doubt. The Cirripedia and Entomostraca, third and fourth types, stand properly on nearly the same level.
On the following pages, we offer a review of the classification of Crustacea, with the characters of the several subdivisions.* We first present the characters of the higher divisions of the class, that is
The SuBCLASSES, ORDERS, and Tries of Crustacea.
* References and synonymy are omitted beyond, as they have been given fully in other parts of the work.
CRUSTACEA.
SuscLassis I. PODOPHTHALMIA (ver DECAPODA).
Annuli cephalothoracis cephalici (ad sensus et appendices buccales pertinentes) numero novem. Oculi pedunculati. Branchiz aut folioss: aut filose, sub thoracis lateribus disposite, raro obsolete vel abdominales. Cephalothorax carapace plus minusve tectee.
Orvo I. EUBRANCHIATA.
Branchie apud thoracis latera disposite, carapace tecte.
Trius I. BRACHYURA.—Corpus latum. Abdomen in sternum inflexum et stricte appressum, appendicibus carens. Branchiz utrinqgue numero novem. Vulve in sternum excavate. Carapax sutura, longitudinali infra utrinque notatus, antice cum epistomate coalitus.
Trisus Il. ANOMOURA.—Corpus sive latum sive multum elon- vatum. Abdomen sepe ac in Brachyuris, sepe ad sternum laxe appressum, interdum elongatum, et non inflexum, et appendicibus caudalibus instructum raro appendicibus aliis. Branchiee utrinque numero novem vel plures. Vulvz in pedum 3tiorum bases exca- vate, ac in Macrouris, Carapax suturd longitudinali utrinque notatus, ac in Brachyuris.
Trisus II. MACROURA.—Corpus multum elongatum. Abdomen elongatum et appendicibus seriatis instructum, vix inflexum, vel
ern eR
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CLASSIFICATION OF CRUSTACEA. 1416
rectum. Branchia numero seepius plures quam novem. Vulvze in pedum 3tiorum bases excavate. Carapax sutura longitudinali
raro utrinque notatus.
Orpo II. ANOMOBRANCHIATA.
Branchie sive apud pedum bases thoracis disposite et aperte, sive appendicibus abdominis appendiculate, sive omnino obsolete.
Trizus I. MYSIDEA.—Corpus forma fere Caridoideum, non depres- sum. Pedes thoracis et maxillipedes nulli prehensiles, graciles, seepius palpigeri, palpo prope thoracem insiti.
Trius Il AMPHIONIDEA.—Corpus depressum, sepe latum. Pedes thoracis et maxillipedes nulli prehensiles, palpigeri, palpo a thorace remoto.
Tripus III. SQUILLOIDEA.—Corpus valde depressum. Pedes qua- tuor et maxillipedes quatuor monodactyli prehensiles.
Susciassis II. TETRADECAPODA.
: Annuli cephalothoracis cephalici numero seplem. Oculi ses- ;. | siles. Appendices branchiales simplicissime:, sive tho- racic sive abdominales. Cephalothorax multi-annulatus,
carapace carens, pedibus seriatis instructus. Abdomen
appendicibus seriatis instructum, raro obsolescens. :
Orpo I. CHORISTOPODA.
Cephalothorax pedibus unguiculatis interdum partim chelatis in- structus, pare utroque ad annulum singulum pertinente.
Tripus L ISOPODA.—Pedes thoracis seriei anterioris numero sex seriei posterioris octo, appendicibus branchialibus non instructi. Abdomen breve, appendicibus decem anticis branchialibus, duobus posticis styliformibus vel lamellatis.
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1416 CRUSTACEA.
Trisus II. ANISOPODA.—Pedes thoracis seriel anterioris numero octo, seriei posterioris numero sex, appendicibus branchialibus non instructi. Abdomen sat breve, appendicibus decem anticis branchi- alibus vel subnatatoriis, duobus posticis ac in Jsopodis.
Tripus III. AMPHIPODA.—Pedes thoracis seriei anterioris numero octo, seriei posterioris numero sex, appendicibus branchialibus partim instructi. Abdomen elongatum, appendicibus sex natatoriis sex styliformibus instructi.
Orvo II. TRILOBITA.—(An hujus sedis ?)
?—Cephalothorax appendicibus lamellatis infra instructus haud pedi- bus unguiculatis. Segmenta corporis numero ab norma sepe mul- tiplicata.
Suscuassis IIT. ENTOMOSTRACA.
Annuli cephalothoracis cephalici numero sex vel quinque. Oculi seepissime sessiles. Appendices branchiales sepis- sime nulla. Abdomen appendicibus seriatis non instruc- tum. Cephalothorax pedibus seriatis instructus, octo vel decem posticis ad annulos 8vum—l1mum vel 12mum perti- nentibus (si non obsoletis), seepius natatoriis.
Orpvo I. GNATHOSTOMATA.
Os mandibulis maxillisque normalibus instructum, non trunciforme nec suctorium.
Lxcio I. LOPHYROPODA.—Appendices cephalothoracis et segmenta numerum normalem non superantes,
Trisus I. CYCLOPOIDEA.—Cephalothorax annulatus et carapace non instructus. Abdomen rectum et non inflexum. Appendices
CLASSIFICATION OF CRUSTACEA. 1417
cephalothoracis mandibulares et sequentes numero 16-18, posticis 8-10 natatoriis.
Trinvs Il. DAPHNIOIDEA.—Corpus carapace plerumque tectum, abdomine plus minusve inflexo. Appendices cephalothoracis man- dibulares et sequentes numero 12-16, 6-8 posticis subnatatoriis.
Trinus III. CYPROIDEA.—Corpus carapace bivalvi omnino tectum
et bene clausum, abdomine bene inflexo. Appendices cephalotho- racis mandibulares et sequentes numero 10, nullis natatoriis.
Lxcio I. PHYLLOPODA.—Appendices segmentoque cephalothoracis
numerum normalem superantes, corpore immodicé annulato.
Trisus I. ARTEMIOIDEA.—Corpus fere rectum. Cephalothorax multiannulatus test’ sive tectus sive non tectus. Appendices cephalothoracis plerumque foliacese. Oculi pedunculati. Styli caudales fere ac in Cyclopoideis.
Trisus II. APODOIDEA. — Cephalothorax test& scutiformi tectus. Appendices, cephalothoracis posteriores lamellate. Oculi sessiles Abdomen multiannulatum. Extremitas caudalis forma mirabilis.
Trrpvs IIL. LIMNADIOIDEA.—Corpus test& omnino tectum capite abdomineque inclusis ac in Cyproideis. Oculi sessiles. Extremitas caudalis ac in Cyproideis.
Orvo II. CORMOSTOMATA.
Os trunciforme et suctorium, basi seepe mobile.
Suzorpo I. PAACILOPODA.
Quoad formam corporis Cyclopoideis plerumque aflinia, seepe peltata, interdum subcylindrica, quoque vermiformia. Os inferius.
Trieus L. ERGASILOIDEA.—Cephalothorax annulatus, carapace non tectus. Truncus buccalis non mobilis, brevis, mandibulis in- terdum obsoletis (?). Pedes 8 postici bene natatorii ac in Cyclopoi-
deis. Ova externa in sacculos gesta. Corpus seepius non depressum. 359
a eee le — a = amr: = Ne —
= center ea - = r ame. a oie GRD a
Se et ae ee yng set sae ame OS r — =e
aiden ae
1418 CRUSTACEA.
Trisus I]. CALIGOIDEA.—Cephalothorax sive annulatus sive cara- pace tectus. Truncus buccalis mobilis, mandibulis armatus. Pedes 8 postici plus minusve natatorii, sepe partim in laminis coaliti, Ova externa in tubos longos uniseriatim gesta, tubis raro obsoletis. Corpus seepius valde depressum et peltatum.
Trpus III. LERNAOIDEA.—Cephalothorax vix annulatus. Cor- pus sive breve et obesum sive elongate vermiforme. Pedes nata- torii obsoleti. Ova externa sive in sacculos aggregata sive in tubos uniseriata. |
Suzorpo II. ARACHNOPODA. Quoad formam corporis fere Arachnoidea, abdomine plerumque obso-
leto, cephalothorace brevi, annulato, pedibus longis diffusis. Os trunciforme frontale.
Trius PYCNOGONOIDEHA.
Orvo III. MEROSTOMATA. Os pedum basibus in locis mandibularum et maxillarum instructum.
Trius LIMULOIDEA..
Susciassis IV. CIRRIPEDIA.
Annuli cephalothoracis cephalici numero sex vel quinque. Oculi sessiles vel obsoleti. Appendices branchiales nulle. Abdomen obsoletum. Animal sessile in testam multival- vatam inclusum qua nunquam in nulla parte extus exuitur. Cephalothorax pedibus seriatis tenuibus multiarticulatis instructus.
CLASSIFICATION OF CRUSTACEA,
SuzpcLassig V. ROTATORIA.
Corpus minutum, pedibus totis carens et ciliis motum. Ab- domen sepe 2-3 annulatum et apice furcatum, interdum obsoletum. Annuli cephalothoracis cephalici numero quin- que vel quatuor.
After this exposition of the subclasses, orders, and tribes, of the class Crustacea, here follows
gia Se Get h ax ey ey.
OF THE FAMILIES AND SUBFAMILIES OF THE HIGHER SUBDIVISIONS OF CRUSTACEA.
Suscrassis I. DECAPODA. Orvo I. HUBRANCHIATA. Trisus I. BRACHYURA. Susrraisus I. MAIOIDEA..
Lzgio I. MAIINEA vel Matomwsa Tyrica.—Corpus seepissime oblon- gum, sepius antice angustum et rostratum. Articulus antennarum externarum Imus sub oculo insitis, anteriusque productus, testa externa sine sutura coalitus. Pedes forma normales.*
* We have modified the arrangement of the Maioidea, by separating from the family Maiade, the families Inachide and Mithracide. The peculiarity of the outer maxilli- peds, adopted by De Haan as the characteristic of the Inachidz, appears to be of suffi- cient value to authorize the separation of the genera of this kind from the other Maiide, although not so important as to require the union of the Hurypodii with the Inachide, as done by this author. The Mithraces have a distinct character, removing them from the other Maioids. There is in the species Mithrax, a singular diversity of form
1420 CRUSTACEA.
Fam. I. INACHIDA).—Oculi in orbitis retractiles. Articulus max- illipedis externi 3tius apice 4tum gerens. Digiti acuminati. [Pedes preelongi. |
1. Macrocnrtrina.—Carapax late ovatus. Rostrum furcatum. Oculi oblongi. —G. Macrocheira, De H.
2. Inacuinm.—Carapax triangulato-ovatus. Rostrum emarginatum aut integrum. —G. Inachus, Fab., Microrhynchus, Bell.
8. SaLactnm.—Oculi perbreves. Rostrum fere obsoletum, non bifidum. Corpus non oblongum. Pedes 8 postici longi et crassii—G. Salacia, H. and Lucas.
Fam. IT. MAIIDA®.—Oculi in orbitis retractiles. Articulus maxil- lipedis externi 3tius angulo interno 4tum gerens. Digiti acuminati.
1. Oculi latera capitis insite et plus minusve lateraliter porrectt.
1. Linryinz.—Rostrum apice emarginatum. Corpus: paulo oblongum, subglo- bosum, lateribus altis. Oculi perbreves. Pedes sive longi sive mediocres.—G. Ligeria, Lat., Doclea, Leach, Libidoclea, HK. and L., Libinia, Lh.
. Matina.—Carapax orbiculato-ovatus, rostro prominente profundé bifido. Pars antennarum externarum mobilis margine orbite orta.—G. Maia, Lk., Dione, De H. . Pistna.—Carapax triangulato-ovatus, rostro bifido, non deflexo. Pars anten- narum externarum mobilis margine orbits exclusa, et sub rostro non celata.—@G. Paramithrax, 4., Pisa, Uh., Pelia, Bell, Lissa, Lh., Rhodia, Bell, Hyas, Lh., Pisoides, EK. and L., Herbstia, H., Thoe, Bell, Dehaanius, M’L.
. PrionorHYNCHINA.—FPisinis affines. Rostrum breve, latissimum, bilobatum, non deflexum.—G. Prionorhynchus, H. and J.
. Micrepina.—Rostrum latum, deflexum.—G. Micippa, Lh.
. CHORININ#Z.—Carapax triangulato-ovatus. Rostrum furcatum. Pars anten- narum externarum mobilis sub rostro celatii—G. Chorinus, Lh., Chorilia, D Lahaina, D., Naxia, K., Scyra, D., Hyastenus, White, Pyria, D.
ba
2. Oculi frontales et porrecti longitudinales, carapace antice truncato.
7. Ornontin#.—Oculi elongati, cylindrici.—G. Othonia. [Cujus sedis est Siphonecetes, Kr. ]
Fam. II. MITHRACIDAi.—Oculi et maxillipedes externi ac in Maiidis. Digiti versus apicem excavati et non acuminati.
1. Mrraractn#.—Oculi longitudine mediocres.—G. Mithrax, Lh., Mithraculus, W. 2. Crctacina.—Oculi longi.—G. Cyclax, D.
exceeding what is found in any other genus of Maioidea. This fact, in connexion with the habits of the species, and the peculiarity of the fingers, seems to require the institu- tion of a distinct family of Mithracide.
CLASSIFICATION OF CRUSTACEA. 1421
Fam. IV. TYCHIDAi.—Oculi retractiles sed orbitis carentes, infra carapacem sese latentes. 1. Crrocarcinina.—Rostrum valde deflexum. Carapax oblongus.—G. Criocar-
cinus, Guer. 9. Tyouin.—Carapax oblongus, antice latus, latitudine trans-orbitali magna,
rostro non deflexo, sat longo, furcato. Oculi apice paululum exserti-—G. Zyche, Bell. .
3. Camposctn«.—Carapax oblongus, rostro fere obsoleto, emarginato. Pedes 8 postici longi. Oculi elongaté pedunculati et exserti.—G. Camposcia, Lat.
Fam. V. EURYPODID.—Oculi retractiles ad carapacis latus, non sese latentes.
1. Eurypoprina.—Antennx externe aperte. Carapax triangulato-ovatus, rostro longo, furcato. Pedes longi. Oculi longi et elongate salientes. Spina post- orbitalis oblonga.—G. Hurypodius, Guer., Oregonia, D.
2. Amatuin#.—[An oculi retractiles et species hujus sedis?] Antenne externze sub rostro celate. Carapax triangulato-ovatus, rostro furcato, latitudine trans- orbitali perangusta. Pedes longi—G. Amathia, Roux.
Fam. VI. LEPTOPODID.—Oculi non retractiles. Pedes prelongi.
A. Antenne extern aperte.
1. Acuainm.—Carapax triangulato-ovatus, rostro perbrevi, bifido. Oculi longi et elongate salientes. Pedes 4 postici subprehensiles.—G. Achcws, Lh. 9. INACHOIDIN/!.—Carapax triangulato-ovatus, rostro elongato, simplice.—G. Ina-
choides, K. and L. m
B. Antenne extern sub rostro celate.
3. Lepropopina.—Carapax triangulato-ovatus, rostro elongato, simplice. Pedes
longissimi.—G. Leptopodia, Lh. 4, SrenoRHYNCHIN#.—Carapax triangulato-ovatus, rhynchus, Lk.
rostro breve, bifido.—G. Steno-
Fam. VII. PERICERID.A.—Oculi non retractiles. Pedes longitu- dine mediocres. |
A. Antenne externe aperte.
1. Paramicrppin£.—Rostrum valde deflexum. Micippe aspectu similes.—G. Paramicippa, EK. : 9, PreRICERINE.—Rostrum profundé bifidum, non deflexum.—G. Pericera, Lat., Tiarinia, D., Perinia, D., Halimus, Lat., Pugettia, D. 856
1422 CRUSTACEA.
3, MenarTnin#.—Rostrum integrum vel subintegrum.—G. Menzthius, H., Acan- thonyx, Lat., Antilibinia, M’L., Peltinia, D.
B. Antennze externe sub rostro celatx.
4, SrENocIoNoPINa. —Oculi prelongi. Rostrum longum, furcatum, ~cornibus styliformibus, divaricatis.—G. Stenocionops, Lat.
5, EpraLtin£.—Oculi longitudine aut mediocres aut perbreves. Rostrum oblon- gum, crassum, sive integrum, sive emarginatum. Antenne externe apicem rostri sepius non attingentes. Pedes 8 postici subcylindrici—G. Epiadltus, E., Huenia, De H., Xenocarcinus, W., Leucippa, H.
Lecio Il. PARTHENOPINEA vel Matomga Cancripica.—Corpus sive breviter triangulatum sive valde transversum et antice arcu- atum. Articulus antennarum externarum Imus oculo interior, rarissimé solutus, sepius suturd infixus, raro sine sutura externa coalescens. Pedes antici longiores, toti forma normales.
Fam. I. PARTHENOPIDA.—Oculi retractiles. Carapax lateraliter °
non bene expansus. G. Parthenope, Fab., Lambrus, Lh., Hurynome, Lh.
Fam. Il. EUMEDONIDA.—Oculi non retractiles. Carapax late-
raliter non bene expansus.
G. Eumedonus, B., Ceratocarcinus, W. (Harrovia, W.) [An hujus sedis Gonato- notus, A. and W. Crust. Sam., tab. vi. f 7.]
Fam. II. CRYPTOPODIDA,—Oculi retractiles. Carapax latera- liter valde expansus, pedes 8 posticos plerumque tegens. G. Cryptopodia, H., Eurynolambrus, H., Tlos, W. Fam. IV. TRICHIDA.—FParthenopidis quoad oculos carapacemque affinis; sed quoad maxillipedes externos Dromus. G. Trichia, De H.
Lecio III. ONCININEA vel Matomwza Dromipica.—Corpus triangu- latum. Antenne externa: e basi solute, cylindricee. Pedes pos- tici breviores, subdorsales, uncinato-prehensiles.
Fam. I. ONCINOPID. G. Oncinopus, De H.
CLASSIFICATION OF CRUSTACEA.
Suprrisus II. CANCROIDEA.
Lecio I. CANCRINEA vel CANCROIDEA TypicA.— Species marin
vel maritime. Antenne quatuor conspicue. Cavitas branchialis
superficie non papillo-spongiosa. p g
1. Pedes postici gressorit.
Fam. I. CANCRIDA.—Palatum colliculo longitudinali utrinque non bene divisum. Carapax seepius late transversus, interdum angustus.
Antenne interne plus minusve longitudinales.
1. Canorinai.—Frons interorbitalis perangustus. G. Cancer, Leach, Pert-
mela, Lh. Fam. Il. XANTHID.—Palatum et carapax ac in Cancridis. An- tennee interne plus minusve transverse. 1. Xanruina.—Antenne externz basi firmé infixee, parte mobili ex hiatu orbite non exclusi. rons interorbitalis latior. Digiti acuminatii—G. Atergatis, De H., Carpilius, Lh., De H., Liomera, D., Liagora, De H., Actea, De H., D., Xantho, Lh. (subgenera Xantho, Euxanthus, D., Xanthodes, D., Paraxanthus,
Lucas), Menippe, De H., Panopzus, B., Medxus, D., Halimede, De H. } 2. CHLoRODINZ.—Antennee interne transverse. Antenne externe basi firme 1 | infixee, parte mobili ex hiatu orbitze raro exclus’. Frons interorbitalis latior. bit! Digiti instar cochlearis excavati. [Quoad genera Xanthine et Chlorodinz ferme hh parallela.|—G. Etisus, Lh., Carpilodes, D., Zozymus, Lh., Actzxodes, D., Daira, i)
De H., Chlorodius, Lh. (subgenera Chlorodius, Pilodius, D., Cyclodius, D.), Cymo, De H.
3. PotypECTIN/.—Antenne interne transverse. Antenne extern et libera.—[An Pilumnis propinquior.]—G. Polydectus, K.
xe basi solutee
Fam. III. ERIPHIDA.—Palatum colliculo longitudinali utrinque bene divisum. Carapax seepius angustus, interdum latus, margine antero-laterali raro longiore quam postero-lateralis, latitudine ante- medianA ssepissimé longiore, oculis remotis.
1. Grurin.a.—Carapax transversus, lateribus valde dilatatis et rotundatis. An- tennze internee fere longitudinales.—G. Gthra, Lh. 2. Ozinm.—Carapax plus minusve transversus, lateribus non dilatatis. Digiti % acuminati. Antenne interne transverse. Orbita hiatu interno basi antennse occupato instructa. Abdomen maris 7-articulatum.—G. Galene, De H., Ozius, E., Pseudozius, D., Pilumnus, Lh., Pilumnoides, H. and L., Melia, H. [An
hujus sedis Acanthodes, De H.?] 3. AcrumMNINa.—Orbita Ozinis similes.
Digiti instar cochlearis excavati.—G.
Actumnus, D.
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menace
1424 CRUSTACEA.
4, Errpnin.—Orbita infra bene clausa, hiatu interno carens, articulo antennz basali ex orbité omnino excluso. Carapax sive paulo transversus sive subquad- ratus. G. Ruppellia, B., Eriphia, Lat., Domecius, Souleyet, Trapezia, Lat., Tetralia, D., Quadrella, D.
2. Pedes postict natatori.
Fam. IV. PORTUNID.— Ramus maxillipedis lmi internus lobo interno instructus. Palatum sapius colliculo longitudinali utrin- que divisum.
1. Luprva.—Sutura sterni mediana tria segmenta intersecans. Palatum colli- culis prominentibus.—G. Scylla, De H., Lupa, Lh., Amphitrite, De H., D., Carupa, D., Thalamita, Lat., Charybdis, De H., D., Lissocarcinus, W.
2. AREN&INA.—Sutura sterni mediana tria segmenta intersecans. Palatum col- liculis non divisum. Ramus maxillipedis 1mi internus ad apicem late transversim triangulatus, ramis duobus inter se fere convenientibus.—G. Arenzus, D.
3. Porrunipz.—Sutura sterni mediana duo segmenta intersecans. Palatum col liculis seepe obsoletis.—G. Portunus, Fab.
Fam. V. PLATYONYCHIDA).—Ramus maxillipedis 1mi internus non lobatus. Palatum colliculis non divisum.
G. Carcinus, Lh., Portumnus, Lh., Platyonychus, Lat., Polybius, Lh.
Leqio Il. TELPHUSINEA vel CancromEa GrapsiDica. — Species fluviales. Antenne quatuor conspicue. Cavitas branchialis per- magna ac in Grapsoideis, superficie seepe papillo-spongiosis.
Fam. I. TELPHUSID A.
G. Telphusa, Lat., Valdivia, W., Potamia, Lat., Trichodactylus, Lat., Orthostoma, Randall.
Lzcro III. CYCLINEA vel Cancrorpra CorystipicA.—Antenne ex- terns obsolete. Carapax angustus vel suborbicularis.
Fam. I. ACANTHOCYCLID 4. G. Acanthocyclus, Lucas.
Susrrizsus III. CORYSTOIDEA.
Fam. I. TRICHOCERID.A.—Carapax forma Cancroideus, fronte non rostratus. Antenne interne longitudinales. Antenne externe
CLASSIFICATION OF CRUSTACEA. 1425
breves, flagello parce piloso. Maxillipedes externi super epistoma non producti, sed marginem ares buccalis bene adaptati.
G. Trichocera, De H.
Fam. II. THIIDAS.—Carapax suborbicularis, non oblongus, fronte non rostratus. Antenne interns transverse vel oblique. An- tenn externe breves, flagello parce-piloso. Maxillipedes externi super epistoma producti.
G. Thia, Lh., Kraussia, D.
Fam. II. CORYSTID.—Carapax sive suborbicularis sive multum angustus, fronte plus minusve rostrato. Maxillipedes externi super epistoma producti.
G. Telmessus, W., Atelecyclus, Lh., Peltarion, H. and Jacq., Pseudocorystes, K., Gomeza, Gray, Gidia, De H. (partim), Corystes, Lat., Dicera, De H.
Suprrisus IV. GRAPSOIDEA. 1. Articulus mamillipedis externi 4tus cum angulo 3tio interno articulatus.
Fam. I. GONOPLACID 4.—Carapax transversus. Frons 4t& parte latitudinis carapacis longior, paulo deflexus, lamellatus. Antenne interns: transverse. Articulus abdominis maris 2dus sterno con- tiguo angustior.
G. Eucrate, De H., Curtonotus, De H., Gonoplax, Lh.
2. Articulus maxillipedis externi 4tus cwm angulo 3tit apicali interno non articulatus sed medio marginis apicalis sive angulo externo.
Fam. I. MACROPHTHALMID Al. Oculi 3tid parte carapacis non breviores. Carapax subquadratus, seepissime transversus, antice latissimus, angulis anticis acutis, lateribus non arcuatis. Antenne ‘nternse sive transverse sive longitudinales.. Articulus abdominis maris 2dus sterno contiguo angustior. Articulus maxillipedis ex- terni 8tius cristé obliqua piliferé. nunquam ornatus.
1. MAcRopHTHALMIN #.—Antennz interne transversee sub fronte insite. An- tennee externee basi ad frontem appresse. Articulus maxillipedis externi 4tus apertus.—G. Cleistostoma, De H., Macrophthalmus, Lat.
2. Ocypopina.—Antenne interne longitudinales, juxta frontem utrinque insite.
307
: i ' t :
. | |
oe :
Subasltraal ESS rt 7 Pier
CRUSTACEA.
Antenne externz a fronte paulum remote. Articulus maxillipedis externi 4tus apertus, 3tius 2do minor.—G. Grelasimus, Lat., Helecius, D., Ocypoda, Fab., Scopimera, De H.
3. Dorina.—Articuli maxillipedis externi 4tus et sequentes 3tio celati—G. Doto, De H.
Fam. II. GRAPSIDA.—Oculi 3ti& parte latitudinis carapacis bre- viores. Carapax subquadratus, seepius depressus, lateribus aut rectis aut arcuatis. Antennze interne transverse. Articulus abdominis maris 2dus sterno contiguo seepius vix angustior. Arti- culus maxillipedis externi 3tius sive inornatus sive crista obliqua piliferd ornatus. Palatum colliculis (viarum efferentium limitibus) instructum.
1. Grapstna.—Antenne interne fronte tecte. Articulus maxillipedis externi 8tius ecristaé obliqua in 2dum product& non ornatus.—G. Pseudograpsus, H., Hete- rograpsus, Lucas, Platynotus, De H., Brachynotus, De H., Trichopus, De H., Grapsus, Lk., Goniograpsus, D., Planes, Lh., Hemigrapsus, D., Cyrtograpsus, D.
2. SrsaRMiInza.—Antenne interne fronte tectee. Articulus maxillipedis externi 8tius crist& obliqua in 2dum productd notatus.—G. Sesarma, Say, Sarmatium, D., Cyclograpsus, H., Chasmagnathus, De H., Helice, De H.
3. PLagusina.—Antenne interne sinubus frontis longitudinalibus apertee.—G. Acanthopus, De H., Plagusia, Lat.
Fam. IV. GECARCINID #.—Oculi breves. Carapax obesus, paulo transversus, antice latus, curvatim declivis, lateribus arcuatis et pone oculos largé rotundati et vix dentatis. Antenne interne transverse. Articulus abdominis maris 2dus sterno postico vix angustior. Articulus maxillipedis externi 3tius crista obliqua plifera non ornatus. Palatum colliculis (viarum efferentium lmiti- bus) non instructum.
1. Ucatna.—Articulus maxillipedis externi 4tus apertus.—G. Uca, Lh., Gecar- cinicus, ., Cardisoma, Lat., Gecarcoidea, HK.
2. GECARCININA.—Articuli maxillipedis externi 4tus et sequentes 3tio celati.—G. Gecarcinus, Lat.
Fam. V. PINNOTHERID.A. —Oculi perbreves orbitis insiti, raro non retractiles. Carapax sive obesus sive depressus, raro paulo oblongus et interdum parce rostratus, lateribus valde rotundatis. Antenne interne aut transverse aut oblique. Abdomen maris angustum, versus basin sterno contiguo valde angustius. Palatum colliculis (viarum efferentium limitibus) instructum. [Species tote parvee. |
1. Prnnornerin#.—Articulus maxillipedis externi 2dus parvulus aut obsoletus.
CLASSIFICATION OF CRUSTACEA. 1427
Corpus sive obesum sive depressum.—G. Pinnothera, Uat., Fabia, D., Xenoph- thalmus, W., Xanthasia, W., Pinnixa, W., Pinnotherelia, Lucas.
2. Hymenicina.—Corpus seepius parce rostratum, depressum. Articulus maxil- lipedis externi 2dus dimidio 3ti major.—G. Hymenosoma, Lh., Halicarcinus, W., Hymenicus, D., Elamena, H.
Fam. VI. MYCTIRID.Z.—Corpus obesum. Carapax antice peran- eustus, vix rostratus, orbitis carentes. Antenne interne parvule, longitudinales.
G. Myctiris, Lat.
Suprrisus V. LEUCOSOIDEA.
1. Appendices maris genitales basi pedum 5torum orte. [Via afferens pone regtonem pterygostomianam ingrediens. |
Fam. I. CALAPPIDA.—Articuli maxillipedis externi terminales non celati.
1. Canapprna.—Pedes nulli natatorii—G. Calappa, Fab., Platymera, H., Mursia, E., Cycloes, De H. 2. Orrrayina.—Pedes 8 postici natatorii—G. Orithyia.
Fam. Il. MATUTIDAl.—Articuli maxillipedis externi terminales celati, 3tio triangulato, palpo vix longiore quam articulus 2dus.
G. Hepatus, Lat., Thealia, Lucas, Matuta, Fab.
2. Appendices maris genitales sterno orte.
Fam. IU. LEUCOSID 42.—Via afferens apud angulum palati antero- lateralem ingrediens. Articuli maxillipedis externi terminales pre- cedentibus tecti. Pedes postici ad normam gressoril.
G. Philyra, h., Leucosia, Fab., Leucisca, M’L., Ebalia, Lh., Nucia, D., Nursia, Lh., Ilia, Lh., Myra, Uh., Persephona, Lh., Za, Lh., Iphis, Lh., Arcania, Lh., Oreophorus, Riippell.
Fam. IV. DORIPPIDA.—Via afferens partem regionis pterygosto-
miane posticam ingrediens. Articuli maxillipedis externi termi- nales precedentibus non tecti. Pedes 2-4 postici subdorsales pre-
hensiles. G. Dorippe, Fab., Ethusa, Roux.
= ~ ny « “hes come . ee ol Miaka. skal cz Gistaidia " ‘ft Sel eS nme np ‘
CRUSTACEA.
Tripus II. ANOMOURA.
Srectio I. ANOMOURA SUPERIORA.
Oculi antennis lmis non anteriores. Antenne 2de oculis interdum posteriores non exteriores. Abdomen angustum, ad sternum seepius appressum, appendicibus caudalibus carens.
Suprrizus I. DROMIDEA, vel ANoMourA MArrIpicA SUPERIORA.
Carapax subtriangulatus vel subquadratus vel suborbiculatus, fronte angusto, oculis approximatis. Pedes postici subdorsales. Via affe- rens uti in Maioideis.
Fam. I. DROMID Ai. G. Dynomene, Lat., Dromia, Fab., Latreiilia, Roux, Homola, Uh.
Fam. II. CYMOPOLIDA).—[An hujus sedis ?] G. Cymopolia, Roux, Caphyra, Guer.
Susrrinus Il. BELLIDEA, vel ANomourA CANCRIDICA.
Carapax parce oblongus, subellipticus. Pedes 8 postici inter se similes. Via efferens uti in Dromideis.
Fam. I. BELLID Ai. G. Corystoides, Lucas, Bellia, HK. Suprrigus II. RANINIDEA, vel ANomouraA LuvcosIDICca. Carapax oblongus. Via efferens osque uti in Leucosoiders.
Fam. I. RANINIDA. G. Raninoides, H., Ranina, Lk., Ranilia, E., Notopus, De H., Lyreidus, De H.,
Cosmonotus, W.
— — ennai «lilt astiesepcui ae - os i iP gS IO a a rape = wwe ae. aie me ae ae + st RN eg — A OD Rigs er CNIS pene Ra: — ener a ae we ae ee <0 wie ey ~~, “1 ail in - —— onenseme tm — yy ae ; : : ee oe mre : = - - ~~ rreentes
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CLASSIFICATION OF CRUSTACEA.
Sgectio Il. ANomourA MEDIA.
Oculi antennis Imis non anteriores. Antenne: 2de oculis posteriores et exteriores. Abdomen inflexum, sed non stricte appressum, ap- pendicibus caudalibus instructum. Os nunquam uti in Leucosoi- deis.
Susprrisus IV. HIPPIDEA, vel ANoMouRA CoRysTIDICA.
Carapax oblongus. Maxillipedes externi operculiformes, articulo 3tio elongato et lato. Pedes 2di 3tii 4tique natatorii, 5ti debiles inflexi.
: Fam. HIPPIDAL. G. Albuncea, Fab., Albunhippa, E., Remipes, Lat., Hippa, Fab.
Suprrisus V. PORCELLANIDEA, vel ANOMOURA GRAPSIDICA. Carapax suborbiculatus. Maxillipedes externi male operculiformes, articulo 3tio paulo minore quam 2dus. Pedes 2di 3tii 4tique gres-
sorii, 5ti debiles, inflexi.
Fam. PORCELLANID.
G. Porcellana, Lamarck.
Srctio III. ANOMOURA SUBMEDIA.
Oculi antennis Imis plane anteriores. Abdomen valde dilatatum, inflexum sed stricte non appressum, appendicibus caudalibus carens.
Suprrisus VI. LITHODEA, vel ANomouRA Matipica SUBMEDIA.
Carapax subtriangulatus uti in Maioideis. Abdomen latum, vix sym- metricum. Pedes nulli natatorii, 2dis 3tiis 4tisque consimilibus,
5tis parvulis, sub carapace inflexis. 308
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1430 CRUSTACEA.
Fam. LITHODID. G. Lithodes, Lat., Lomis, De H., Echidnocerus, W.
Sectio IV. Anomoura INFERIORA.
Oculi antennis Imis anteriores. Antennze 2de oculis posteriores et exteriores. Abdomen elongatum, vix inflexum, appendicibus cau- dalibus instructum, seepe appendicibus quoque ventralibus.
Susrripus VII. PAGURIDEA, vel ANoMoURA Mamprca INFERIORA.
Carapax oblongus, postice mollior. Abdomen plerumque molle vel carnosum, appendicibus imparibus sepius instructum. Pedum pares 3tii 4ti dissimiles.
Fam. I. PAGURIDAi.—Antennx interne mediocres, articulo Lmo brevissimo. Maxillipedis externi palpus flagello multiarticulato instructus.—Species aquaticee vel littorine.
1. Pacurina.—Abdomen asymmetricum.—G@. Pagwristes, D., Diogenes, D., Bern- hardus, D., Pagurus, Calcinus, D., Aniculus, D., Clibanarius, D. 2. CANCELLINA.—Abdomen symmetricum.—G. Cancellus, KH.
Fam. II. CENOBITID.4.—Antennez interne multo elongate, arti- culo 1mo oculis ssepius longiore, valde deflexo. Maxillipedis ex- terni palpus flagello non instructus. Species precipue terrestriales.
G. Cenobita, Lat., Birgus, Lh.
Suprrisus VILL. ASGLEIDEA.
Carapax elongatus, textura omnino crustaceus. Abdomen extus crus- taceum, maris paribus appendicum obsoletis, femine elongatis, instructum. Pedum pares 3tii 4tique consimiles; 5ti debiles, sub carapace inflexi. Branchis filosee.
Fam. AXGLEID A. G. diglea, Lh.
CLASSIFICATION OF CRUSTACEA.
Susrrisus IX. GALATHEIDEA.
Carapax elongatus, textura superficiel omnino crustaceus. Abdomen extus crustaceum, maris femineeque paribus appendicum elongatis infra instructum. Pedum pares 3tii 4tique consimiles, dti debiles juxta carapacem inflexi. Branchis foliose.
Fam. GALATHEID As. G. Munida, Lh., Galathea, Fab., Grimothea, Lh.
APPENDIX. MEGALOPIDEA.
G. Marestia, D., Monolepis, Say, Megalopa, Lh., Cyllene, D., Tribola, D.
Trisus III. MACROURA. ;
Sectio I. MAcrourA PAGURO-SQUILLIDICA.
Susrrinus I. THALASSINIDEA.
Carapax duabus suturis longitudinalibus subdivisus, seepeque sutura dorsali transversd. Antenne extern squama basali nulla vel parva instructs. Pedes 6 postici directione non consimiles; duo antici longiores et crassiores, fossorii et seepius chelati.
Lucio I. THALASSINIDEA EUBRANCHIATA.— Species bran-
chiis thoracicis instructze tantum.
Fam. I. GEBID4!.—Mazxillipedes externi pediformes. Appendices caudales et alise abdominales late. G. Gebia, Lh., Awius, Lh., Calocaris, Bell, Laomedia, De H., Glaucothoe, Ki.
a
Fam. II. CALLIANASSID AX.—Maxillipedes externi operculiformes. _ Appendices caudales late.
aiieninad
Sr Sah
G. Callianassa, Lh., Trypxa, D.
—
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1432 CRUSTACEA.
Fam. III. THALASSINID A. — Maxillipedes externi pediformes. Appendices caudales lineares.
G. Thalassina, Lat.
Lzecio II. THALASSINIDEA ANOMOBRANCHIATA. — Pedes
abdominis appendicibus branchialibus instructi.
Fam. I. CALLISEID Ai. G. Callianidea, B., Callisea, Guer., D.
Sectio II. Macroura NorMALIA. Susrrisus I. ASTACIDEA, vel Macrovura SUPERIORA.
Carapax sutura dorsali transversa seepius notatus, suturis longitudi- nalibus obsoletis, testa antero-laterali cum epistomate connata. Antenne extern squama basali sive nulla sive parva instructe. Pedes 6 postici directione sat consimiles; antici crassiores, sive didactyli sive non didactyli. [Branchize filose. ]
1. Antenne extern squamda basali carentes. Pedes antici monodactyl.
Fam. I. SCYLLARIDA).—Carapax valde depressus, margine cepha- lothoracis utrinque tenui, carapace lateraliter subito inflexo. An- tennee externee laminate breves. Sternum trigonum.
G. Scyllarus, Fab., Arctus, D., Thenus, Lh., Parribacus, D., Ibacus, Lh.
Fam. II. PALINURIDA.—Carapax subcylindricus, lateraliter late rotundatus. Antenne extern basi subcylindrice, longee. Sternum trigonum.
G. Palinurus, Fab., Panulirus, Gray.
2. Antenne: extern squama basali instructe. Pedes antict didactyli.
Fam. III. ERYONIDA).—Carapax non oblongus, depressus, lateribus
subito inflexis, abdomine multo angustiore.
G. Eryon, Desmarest.
CLASSIFICATION OF CRUSTACEA. 1433
Fam. IV. ASTACIDAl.—Carapax oblongus, subcylindricus, abdo- mine parce angustiore. Sternum angustum.
1. Astacinm.—Manus crasse et late, superficie convexee.—G. Homarus, H., Asta- coides, Guer. (subgenera Astacoides, Cheraps, Hrich.) Astacus (subgenera Astacus, Cambarus, Erich.)
2. NepHRopIna.—Manus prismatic, lateribus fere rectee.—G. Nephrops, Lh. Paranephrops, W.
Suprrisus II. CARIDEA, vel Macroura Typica.
Carapax sutura nulla notatus, epistomate antice non connatus. An- tenn externs squama basali magna instructe. Pedes 6 postici directione sat consimiles; Imi vel 2di crassiores et chelati, 3tii 4tis similes. [Branchise foliose. ]
1. Maxillipedes 2di breves et lamellati.
Fam. I. CRANGONIDAS. — Mandibule graciles, valde incurvate, non palpigeree, corona perangusta, non dilatata. Pedum pares lmi 2dique inter se valde inzequi.
1. CRaANGoniInNz/.—Pedes Imi 2dis crassiores. Maxillipedes externi pediformes. Digitus mobilis in manus marginem claudens; immobilis spiniformis. Pedes 2di non annulatii—G. Crangon, Fab., Sabinea, Owen, Argis, Kr., Paracran- gon, D.
2. LysmMATINa”.—Pedes Imi 2dis crassiores. Maxillipedes externi pediformes. Digiti subszequi, uno ad alterum claudente. Pedes 2di annulatii—G. Nika, Risso, Lysmata, Risso, Cyclorhynchus, De H.
3. GNATHOPHYLLINZE. — Pedes 2di Imis crassiores. Maxillipedes externi lati,
operculiformes.—G. Gnathophyllum.
Fam. II. ATYIDA1.—Mandibulez crassx, non palpigerse, corona lata, parce bipartit, processu terminali brevi et dilatato. Pedum pares Imi 2dique inter se sequi, carpo nunquam annulato.
1. Aryina.—Pedes thoracici palpo non instructi.—G. Atya, Lh., Atyoida, Ran-
dall, Caridina, H. 2. Hpuyrina.—Pedes thoracis palpo instructi—G. Ephyra, Roux.
Fam. II. PALASMONIDAX.— Mandibule crasse, sive palpigeras sive non palpigere, supra profunde bipartite, processu apicali ob- longo, angusto.
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1434 CRUSTACEA.
1. Atpuern.—Pedes Imi crassiores, chelati; 2di filiformes, carpo seepius annu- lato, plerumque chelato. Mandibulz palpigere.—G. Alpheus, Fab., Betzus, D., Alope, W., Athanas, Lh., Hippolyte, Lh., Khyncocinetes, E.
2. Panpatina.—Pedes tmi gracillimi, non_chelati, 2di filiformes, carpo annulato. —G. Pandalus, Lh.
3. PALMMONINA”.—Pedes 4 antici chelati, 2di Imis crassiores, carpis nullis annu- latis. Pedes nulli palpigeri—G. Pontonia, Lat., D., Gdipus, D., Harpilius, D., Anchistia, D. (An Periclimeni Coste similis ?) Palemonella, D., Palemon, Fab., Hymenocera, Lat., Cryphiops, D. [Hic Zypton Coste, si non squama an- tennarum basalis nulla. ]
4. OpLopHORINE!.—Pedes Imi sive didactyli sive monodactyli; 2di chelati, cras- siores. Squama antennarum externarum acuminata, extus spinis armata,—G. Oplophorus, E., Regulus, D.
[Cujus sedis Autonomea, Risso ?]
2. Mamillipedes 2di tenuiter pediformes.
Fam. IV. PASIPH HID A.—Mandibule uti in Atyidis. G. Pasiphexa, Sav..
/
Susrrisus III. PEN ASIDEA, vel Macroura INFERIORA.
Carapax sutura nulla notatus, cum epistomate antice non connatus. Antenne extern: squama basali magna instructe. Pedes 1mi Qdique 3tiis non crassiores, 3tii seepius crassiores longiores et che- lati; raro pedes toti debiles et tenues, 3tiis sive obsolete chelatis sive non chelatis. —
Fam. I. PEN ©ID-4.—Pedes 6 antici chelati, 3tii longiores et plus minusve validiores. |
G. Sicyonia, B., Penseus, Lat., Aristeus, Duy., Stenopus, Lat., Spongicola, De H.
Fam. II. SERGESTID.—Pedes toti debiles, 2di 3tiique consimiles, sive obsolete didactyli sive non didactyli. Maxillipedes externi tenues.
G. Sergestes, E., Acetes, E., Huphema, BH. (An hujus sedis ?)
Fam. III. EUCOPIDAl.—Pedes toti debiles, 2di 3tiique non chelati, 1mi maxillipedesque externi monodactyli et subprehensiles.
G. Eucopia, D.
\
CLASSIFICATION OF CRUSTACEA. 1435
Orvo II. ANOMOBRANCHIATA. Tripus I. MYSIDEA.
Fam. I. EUPHAUSID Ai.—Cephalothorax forma Caridoideus. Pedes thoracis bifidi, appendicibus branchialibus externis.
G. Thysanopoda, H., Euphausia, D., Cyrtopia, D.
Fam. II. MYSIDA.—Cephalothorax forma Caridoideus. Pedes tho- racis bifidi, appendicibus branchialibus carentes.
1. Cynruin.—Pedes abdominis appendicibus branchialibus instructi. Antenne interne biramese, externee squam4 basali instructe.—G. Cynthia, Thompson.
2. Mystnam.—Pedes abdominis appendicibus branchialibus carentes. Antenne interne birames, extern squama basali instructee.—G. Mysis, Lat., Promysis, D., Macromysis, W., Siriella, D., Loxopis, D.
3. ScELETININaE.—Pedes abdominis appendicibus branchiiformibus carentes. An- tenne interne simplices, externe biramee, squama basali carentes.—G. Scele- tina, D., Rachitia, D., Myto, Kr.
Fam. III. LUCIFERIDAi.—Segmentum antennale valde elongatum carapace per suturam fere discretum. Pedes simplices.
G. Lucifer.
APPENDIX To THE Mysrpra.—G. Furcilia, D., Calyptopis, D., Zoea. Bose.
Tripus IE. AMPHIONIDEA.
Fam. I. AMPHIONIDZ. ; | ah | G. Phyllosoma, Leach, Amphion, Edw. | } i
Trrpus III. SQUILLOIDEA.
Fam. I. SQUILLID..—Rostrum carapaxque per suturam disjuncti. G. Lysiosquilla, D., Squilla, Pseudosquilla, Coronis, Lat., Gonodactylus, Lat. Fam. Il. ERICHTHIDZ.—Rostrum est carapacis frons pois
et acuminatus, carapace et rostro non disjunctis.
G. Squillerichthus, Hdw., Erichthus, Lat., Alma, Lh.
CRUSTACEA.
Suscrassis II. TETRADECAPODA. Orvo I. CHORISTOPODA. Tripus I. ISOPODA.
Suprripus I. IDOTAIDEA.
Appendices abdominales dus posticee bene operculiformes, appendices alias optime tegentes. |
Fam. I. IDOTAIDAi.—Pedes fere consimiles, plus minusve ambu- latoru. G. Idoteea, Fab., Edotea, Guer., Erichsonia, D., Cleantis, D., Epelys, D.
Fam. I. CHATILID .—Pedes 6 postici non subsequi, pari uno lon- gissimo, et multiarticulato. | G. Cheetilia, D. | [An hujus sedis Anthuride. ]
Supremus IL. ONISCOIDEA. »
Appendices abdominales duze posticee styliformes et non operculiformes alias appendices tegentes sat terminales, raro obsolete.
Fam. I. ARMADILLIDAi.—Corpus bene convexum, stricte articu- latum. Abdomen multiarticulatum, segmento ultimo parvo. Ap- pendices caudales ultra abdomen non exsertee, lamellate. Mandi- bule non palpigerss. Antenne: interne inconspicue.
paps ? 1. Tyrinm.—Appendices caudales infra abdominis segmentum posticum celate et operculiformes sed parvee et alias appendices non tegentes.—G. Ziy/us, Lat. 2. ARMADILLIN®.—Appendices caudales inter duo abdominis segmenta postica partim vise.—G. Armadillo, Lat., Spherillo, D., Armadillidium, Br., Diploex- ochus, Br.
Fam. Il. ONISCIDA.—Corpus sepius minus convexum, vel stricte vel laxe articulatum. Abdomen multiarticulatum, segmento ultimo
CLASSIFICATION OF CRUSTACEA. 1437
parvo. Appendices caudales valde exserte, styliformes. Mandi- bule non palpigere. Antenne: interne conspicue.
1. Ontscrn.—Maxillipedes 8-articulati, articulis duobus ultimis brevibus et par- vulis. Antenne externe ad articulationem 5tam bene geniculate. Basis appen- dicum caudalium perbrevis, duos stylos multum inaquos gerens, stylo interno sub abdomine partim celato.—G. Oniseus, Linn. (subgen. Trichoniscus, Br., Por- cellio, Lat., Oniscus), Philoscia, Platyarthrus, Br., Deto, Guer.
2. ScypHactna. — Maxillipedes 2-articulati, articulo 2do lamellato. Antenne externe ad articulationem 5tam non geniculate. Basis appendicum caudalium aut brevis aut oblongus, ramo interno interdum ommino aperto.—G. Scyphaa,
— D., Styloniscus, D.
3. Lyainam.—Maxillipedes 4-articulati, elongati. Antennss externz ad articula- tionem 5tam non bene geniculate. Styli caudales longi, basi longé exserto, ramis setiformibus, subeequis et aque apertis.—G. Lygia, Fab., Lygidium, Br.
Fam. III. ASELLIDA.—Corpus ssepius plus depressum et laxé arti- culatum. Abdomen 1-6-articulatum, segmento ultimo magno, scu- tellato. Appendices caudales styliformes, interdum brevissime. Mandibule palpigerw. Antenne interne conspicue.
1. Limnorina.—Abdomen 5-6-articulatum.—G. Limnoria, Lh.
2. AsELLINa.—Abdomen 1-2-articulatum.—G. Jera, Lh., Jeridina, H., Asellus, G., Janira, Lh., Henopomus, Kr., Munna, Kr.
Susrrisus III. CYMOTHOIDEA.
Appendices abdominales dus postica lamellate, apud abdominis latera dispositee.
Fam. I. CYMOTHOID .—Mazxillipedes breves, 3—4-articulati, oper- culiformes, articulis terminalibus angustis brevibus. Appendices caudales liberx, marginibus rarissimé ciliate. Antenng sub capite infixe. Abdomen 4-6-articulatum, segmentis anterioribus raro connatis. Pedes toti ancorales. Branchie sepissime non ciliate. Epimeree conspicue.
1. Cymoruornm.— Lamelle caudales nude. Abdomen multiarticulatum, seg- mentis liberis.—G. Cymothoa, Fab., Ceratothoa, D., Livoneca, Lh., Anilocra, Lh., Nerocila, Lh., Olencira, Lh.
2. ORozEUKTINE.—Segmentum abdominis posticum ac in Cymothod ; segmenta alia coalita et non libera.—G. Orozewktes, E.
8. AlGATHOINE.—Lamelle caudales ciliate. Abdomen multiarticulatum, seg-
mentis liberis. —G. Aigathoa, D. 360
eam es Ee
1438 CRUSTACEA.
Fam. Il. AGIDA.—Maxillipedes elongati, 4—-6-articulati, articulis totis lamellatis, terminalibus latis et brevibus. Appendices caudales liberee, marginibus ciliate. Antenne ad frontis marginem capitis affixes, apertee. Abdomen 4-6-articulatum. Pedes 6 antici inter- dum ancorales aut prehensiles, seepius simpliciter unguiculati, 8 postici unguiculati et nunquam ancorales. Branchiz ciliate. Epi- — mere conspicue.
1. Alctn#.—Pedes 6 antici ancorales, unguibus validis, reliquis unguibus parvulis confecti—G. Aga, Lh. (Subgen. Alga, Conilera, Lh., Rocinela, Lh.), Ache- rusia, Lucas, Pterelas, Guer.
2. CrroLaANina.—Pedes nulli ancorales.—G. Cirolana, Lh., Corallana, D., Al- tropus, H.
Fam. II. SPHEROMIDAS.— Maxillipedes elongaté 5—6-articulati et palpiformes. Appendices caudales margine abdominis laterali connate. Antenne ad frontis marginem capitis affixe, aperte. Abdomen 1-2-articulatum. Pedes non ancorales (raro 4 antici ancorales). Branchie ciliate. Epimers non discernende.
1. SpHeromina.—Lamella appendicis caudalis externa sub interna se latens.—G. Spheroma, Lat., Cymodocea, Lh., Cerceis, H., Cassidina, H., Amphoroideum, Hi.
2. Neswina.— Lamella appendicis caudalis externa saliens, sub interna se non latens, usquam aperta. Pedes nulli ancorales.—G. Neswa, Lh., H., Campe- copea, Lh. —
3. Ancinina.—Pedes 4 antici ancorales.—G. Ancinus, K.
Trrsus IT. ANISOPODA.
Susrrisus I. SEROLIDEA, vel AniIsopopA CyMOTHOICA.
Appendices dua posticee abdominales lamellate, apud abdominis latera dispositee.
Fam. I. SEROLID.A:.—Appendices abdominales sex antice liber, subnatatorie, quatuor sequentes branchiales, bene lamellatee, ul- time. ac in Cymothoidis. Antenne 1mz sub capite insite.
G. Serolis, Lh. Fam. II. PRANIZIDAi.—Appendices abdominales totee ac in Adgidis.
Antenne 1m sub capite insite. Pedes thoracis numero decem, paribus duobus anticis rudimentariis. Thoracis segmenta numero
quinque non superantia.
——_——
CLASSIFICATION OF CRUSTACEA, 1439
1. Pranizinz.—Caput parvum. Mandibule vix salientes.—G. Praniza, Lh. 2. ANCEIN”.—Caput grande. Mandibule ultra caput longé exsertee.—G. Anceus,
Risso.
Suprrisus Il. ARCTURIDEA, vel AnisopopA Inorzica.
Appendices dus posticee abdominales lamellatz et bene operculiformes, appendices branchiales tegentes.
Fam. I. ARCTURID AL.
1. ArcturiIn#.—Opercula abdominis ad ventrem stricté appressa.—G. Arcturus,
Lat., Leachia, Johnston. 2. AnTHURINa.—(An Idoteideorum?) Opercula abdominis ad ventrem non bene appressa, sed libera et latera abdominis partim tegentia.—G. Anthura, Lh.
Suprrisus III. TANAIDEA, vel Antsopopa ONIscica.
Appendices dus postices abdominales plus minusve styliformes, sub- terminales, interdum obsolete. :
Fam. I. TANAIDAl.—Pedes Imi 2dive subchelati, sequentes non ancorales. Abdomen paribus 5 appendicum subnatatoriis unoque postico stylorum instructum.
1. Tanain.—Corpus lineare, segmento thoracis 1mo seepe oblongo capiteque par- vulo. Styli caudales longi. G. Tanais, H., Paratanaas, D., Leptochelia, D.,
Apseudes, Lh., Rhea, H. 2. Liniopina.—Corpus antice latius, postice sensim angustans, segmento thoracis 1mo reliquis vix longiore, capite sat grandi. Appendices abdominales numero
decem elongate.—G. Liriope, Rathke, Cryptothir, D. 3. CrossurINa#.—Corpus antice latius, postice sensim angustatum, segmento tho- racis Imo vix longiore, capite sat grandi. Appendices abdominales inferiores
numero sex, ciliatee.—G. Crosswrus, Rathke.
Fam. Il. BOPYRIDA).—Pedes toti plerumque aliquo modo subpre- hensiles vel ancorales. Maris corpus angustum ; abdomen 1-6-arti- culatum, appendicibus subnatatoriis stylisque duobus seepe in- structum, totis appendicibus interdum obsoletis. Femince corpus latum et obesum, oculis carens, et quoad pedes seepe partim obso-
letum.
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1440 CRUSTACEA.
1. Bopyrina.—Thorax femine appendicibus branchialibus carens. G. Bopyrus, Lat., Phryxus, Rathke, Cepon, Duv., Dajus, Kr.
2. Iontna. —Pedes thoracis femine ad basin appendices simplices branchiales gerentes.—G. Jone, Lat., Argeia, D.
Tripus II]. AMPHIPODA.
Susrrisus Il. CAPRELLIDEA.
Maxillipedes elongati, palpiformes. Caput oculique mediocres. Ab- domen obsolescens.
Fam. I. CAPRELLIDA.—Corpus longum et fere filiforme. Antenne
2dee longitudine mediocres. [Species non parisitice. | G. Proto, Lh., Protella, D., Capreila, Lk., Zigina, Kr., Cercops, Kr., Podalirius, Kr.
Fam. Il. CYAMIDAi.—Corpus latum, depressum. Antenne Qdee obsolete. [Species parasiticee. |
G. Cyamus.
Susrrisus I. GAMMARIDEA.
Maxillipedes elongati, palpiformes. Caput oculique mediocres. Ab- domen appendicibus sex natatoriis et sex styliformibus instructum.
Fam. I. DULICHIDA).—Gressorie, habitu Caprelloides. Corpus lineare, epimeris obsoletis. Pedes sex posteriores longi, subprehen- siles. Abdomen 6-articulatum.
G. Dulichia, Kr.
Fam. II. CHELURIDA.—Corpus fere cylindricum, epimeris medio- cribus. Abdomen segmentis 4to 5toque coalitis et oblongis, stylis caudalibus inter se valde dissimilibus.
G. Chelura, Philippi.
Fam. III. COROPHIDA. — Gressoris, pedibus partim lateraliter porrectis. Corpus plus minusve depressum, seepe latum, epimeris perbrevibus, interdum obsoletis. Abdomen forma appendicibusque normale et perfectum. Antenne seepe pediformes.
po Sas
CLASSIFICATION OF CRUSTACEA. 1441
1. Cryponin.2.—Styli caudales 1mi 2dique simplices, subulati.—G. Clydonia, D.
2. Coropuina.—Antenne plus minusve pediformes. Styli caudales lmi 2dique biramei.—G. Corophiwm, Lat., Siphonacetes, Kr., Platophium, D., Cyrtophium, D., Unciola, Say, Podocerus, Lh., Cratophium, D., Cerapus, Say, Cerapodina, E., Erichthonius, H.
8. Ioaina.—Antennz non pediformes nec subpediformes, flagellis sat longis basi- que sat brevi instructs. Styli caudales ac in Oorophinis.—G. Icilius, D., Ptery-
gocera, Lat.
Fam. IV. ORCHESTID A. — Saltatoria, pedibus nullis lateraliter porrectis. Corpus compressum, epimeris magnis. Abdomen appen- dicibus normale. Antenns non bene pediformes. Styli caudales Imi 2dique biramei; 3tii simplices brevissimi et ultra 2dos non pro- ducti. Mandibule non palpigeree. Maxille Ime palpo instruct sive parvulo sive obsoleto.
G. Orchestia (subgen. Talitrus, Talorchestia, Orchestia), Allorchestes, D.
Fam. V. GAMMARID.—Saltatorise vel natatori, pedibus nullis lateraliter porrectis. Corpus saplus compressum, raro subde- pressum, epimeris sive magnis sive parvis. Styli caudales laxiores, duobus ultimis oblongis seepiusque ultra 2dos productis, interdum simplicibus. Mandibulee sepissime, palpigeree. Maxille Ime palpo magno 2-8-articulato (rarissime l-articulato) instructe.
1. Pedes 10 postict non prehensiles.
1. SrecocrrHALIN«[.—Antenne breves, superiores basi crass. Mandibule acie denticulata instructe, palpo brevi uniarticulato intus dentato. Epimerz per- magnae.—G. Stegocephalus, Kr.
2. LystANAssina.—Antenne breves, superiores basi crassz. Mandibule apice parce dentate et acuminata, acie vix instructe, palpo 2-3-articulato. Mazxilli- pedes lamellis internis magnis. Epimerz permagne.—G. Lysianassa, E., Phlias, Guer., Opis, Kr., Uristes, D., Anonyx, Kr., Urothoe, D.
8 LxevcoTHoinm.—Antenne superiores basi plus minusve graciles. Maxillipedes elongati, perangusti, articulo longo unguiformi confecti, Jamedlis internis perbre-
-pibus. Mandibule sive palpigers sive non palpigerae, processu molari carentes (An semper?). Hpimerx magnze.—G. Stenothoe, D., Leucothoe, Lh.
(An hujus sedis, genus Michrocheles, Kr., et Amphithoe marionis, Kdw. ?]
4. GAMMARINa.—Antennee Ime basi graciles. Maxillipedes sat lati, lamellis internis sat elongatis. Mandibulee acie denticulatéa instructe et altera accessoria quoque processu molari et palpo 3-articulato. Pedes 10 postici non subprehen- siles. —G. Acanthonotus, Owen, Alibrotus, E., Leptochirus, Zad., Iphimedia, Rath., D., @dicerus, Kr., Amphithoe, Lh., D., Gammarus, Fab., D., Photis, Kr.,
361
—_
ere:
2 ee ARG Ve penning 5 amr > 0 == 2g
ERNIE IN SO OE EN RR ~
eT aa
aes
a Se emcees a " —~ — a
2 A RE A NB -_ “ eae een aetna en - aa —_ anna sie
a amen rn . ae sepupennpigmestee ee
1442 CRUSTACEA.
Melita, Lh., D., Mera, Lh., D., Dercothoe, D., Pyctilus, D., Atylus, Lh., Ischy- rocerus, Kr. [An hujus sedis Pardalisca, Kr.?]
2. Pedes 10 postict partim prehensiles.
5. PonToPpoREINE.—Pedes 3tii 4tique plus minusve prehensiles; 6 postici non prehensiles.—G. Lepidactylis, Say, Pontiporeia, Kr., Ampelisca, Kr., Proto- medeia, Kr., Aora, Kr., Phoxus, Kr.
6. Ism1n.—Pedes 4 vel 6 postici subprehensiles.—G. Jsxa, E., Anisopus, Tem.
Susrrisus II. HYPERIDEA.
Maxillipedes abbreviati, lamellati, operculiformes. Caput grande, oculorum corneis plerumque tectum. Appendices abdominales ac in Gammarideis, latius lamellate.
Fam. I. HYPERIDA1.—Antennz 2dee exserte. Abdomen in ven- trem se non flectens. Pedes 5ti 6ti 7mique forma longitudineque mediocres, tis 6tisve non percrassis nec prehensilibus.
1. Visitina.—Corpus forma paulo Gammaroideum. Caput oculique mediocres. Maxillipedes palpo parvulo instructi. Palpus mandibularis tenuis.—G. Vidi- ha, HK.
2. Hyperina.—Caput tumidum. Oculi pergrandes. Palpus mandibularis tenuis. —G. Lestrigonus, H., Tyro, E., Hyperia, Lat., Metecus, Kr., Tauria, D., Dat- rinia, D. (=Daira, Edw.), Cystisoma, Guer.
3. Synopina.—Corpus gracilius. Palpus mandibularis sat brevis, latissimus. Oculi grandes. —G. Synopia, D. ‘
Fam. Il. PHRONIMID At.—Antennze 2dse exserte. Abdomen in ventrem se non flectens. Pedes dti 6tive sive crassi sive elongati, seepius prehensiles, quoque 3tii 4tique seepe prehensiles.
1. Puronrimina.—Abdomen versus basin sat gracile. Pedes 5ti magné manu didactyla vel monodactyla confecti; 3tii 4ti extremitate graciles, non ae Antenne breves. G. Phronima, is Primno, Guer.
2. PHRosININa.—Abdomen versus es sat crassum. Pedes 5ti prehensiles, monodactyli; quoque 8tii 4tique prehensiles.—G. Anchylomera, E., Phrosina, Risso, Themisto, Guer.
3. Puorcina®.—Pedes 5ti 6tive valde elongati, et crassi, sed manu non confecti.— G. Phorcus, EH. .
Fam. III. TYPHIDA).—Antenne 2dx sub capite thoraceve celatze et ssepius replicate. Abdomen in ventrem szepe se flectens. Pedes
CLASSIFICATION OF CRUSTACEA. 14438
6 postici interdum abbreviati cum articulo 1mo operculiformi, inter- dum longitudine mediocres.
1. Typuina.—Abdomen in ventrem se flectens.—G. Dithyrus, D., Typhis, R. Thyropus, D. .
2. Pronoinz.—Abdomen in ventrem se non flectens. Caput non oblongum, an- tennis in capitis frontem insitis.—G. Pronoe, Guer., Lycea, D.
3. OXYCEPHALIN/Z.—Abdomen in ventrem se non flectens. Caput oblongum antennis Imis in superficiem capitis inferiorem insitis.—G. Oxycephalus, HK. Rhabdosoma, W.
Oro IL. (?) TRILOBITA. -
Supctassis LII. ENTOMOSTRACA. Orvo l. GNATHOSTOMATA. Leeio I. LOPHYROPODA.
Trisus I. CYCLOPOIDEA.
i |
Fam. 1. CALANIDA3.—Oculi duo simplices minutissimi, pigmentis
sive coalitis sive discretis; interdum oculi alii in uno coaliti infra
4 caput deorsum spectantes. Mandibule maxilleeque elongati palpi- gere. Pedes Imi nunquam prehensiles.
Tee
1. CALANINe[.—Oculi inferiores nulli. Antenne Imze longs, fere transversim porrectze; dextra maris articulatione non geniculans; 2de non prehensiles. Max- illae latere interiore setigeree. Abdomen longitudine mediocre.—G. Calanus, Leach, Rhincalanus, D., Cetochilus, Eucheta, Philippi, Undina, D.
9. PonreLtin®.—Oculi inferiores distincti. Antennae Ime longs szpe oblique porrectee; dextra maris articulatione seepius geniculans; 2de non prehensiles. Maxillee abdomenque ac in Calaninis. G. Hemicalanus, D., Diaptomus, Westw., Candace, D., Pontella, Acartia D., Catopia, D.
8 Orrnontna/.—Oculi et antenne fere ac in Calaninis. Abdomen prelongum, cephalothorace vix previus. Maxillee latere interiore digitatze.—G. Ovthona, Baird.
4. Noropenpuina. — Antenne 2de prehensiles, vel monodactyle.—G@. Noto-
. delphys, Allman.
yore
- penser ts 9 ’ =e
= ee enemnsimeeminapes onus eh late
1444 CRUSTACEA.
Fam. Il. CYCLOPIDA.—Oculi duo simplices minutissimi coaliti tantum. Mandibule palpo parvulo vel obsoleto. Pedes 1mi plus
minusve subprehensiles.
1. CycoLopinm.—Sacculi ovigeri externi duo.—G. Cyclops. 2. Harpacricina.—Sacculus oviger unicus.—G. Harpacticus, Edw., Ch ytemnestra,
D., Canthocamptus, Westw., Setella, D
Fam. III. CORYC AID A.—Oculi duo simplices minutissimi coaliti; quoque alii duo portentose magnitudinis, lenticulo prolato interno corneaque magna oblata in testam insita instructi. Sacculi ovigeri sive duo sive unicus. Pedes Imi sxpius subprehensiles.
1. Corvozinm.—Sacculi ovigeri duo.—G. Coryceus, D., Antaria, D., Sapphi-
rina, Thompson. 2. Miracinz.—Sacculus ovigerus unicus.—G. Miracia, D.
Tripus Il. DAPHNIOIDEA.
Fam. I. PENILIDA..—Pedes foliacei numero duodecim, angustiores. Antenne anticee obsolescentes.
G. Sida, Straus, Daphnella, Baird, Penilia, D, Latona, Str.
Fam. II. DAPHNIDA‘.— Pedes foliacei numero decem, latiores.. Antenne antice 1—2-articulate, raro multiarticulate.
G. Daphnia, M., Ceriodaphnia, D., Moina, Baird, Macrothrix, B., Acanthocercus, Schédler, Lurycercus, B., Lynceus, M., Alona, Baird, Bosmina, Baird.
Fam. II. POLYPHEMIDA.—Caput grande, oculis repletum. Pedes numero octo, fere teretes. Antenns antice obsolescentes.
G. Polyphemus, M., Evadne, Loven, Pleopis, D.
Trisus III. CYPROIDEA.
Fam. I. CYPRIDA. — Antenne 2de subteretes, 3—5-articulatee. Mandibule apice producte et denticulate, et lateraliter palpigera, palpo a mandibule apice remoto. Oculi pigmento unico minuto conjuncti, lenticulis duobus sphericis. Pedes duo vel plures tenui- ter pediformes.
ORE wikis pe dina tinh eae "8 ) ceiee Ac lioNlSa
. « eels
CLASSIFICATION OF CRUSTACEA. 1445
1. Cyprina.—Pedes numero quatuor; anteriores tenues pediformes, posteriores . debiles. Abdomen elongatum, stylis duobus, confectum.—G. Cypris, Miiller, a . iI
Candona, Baird. 2. CyrnERIna.—Pedes numero sex, consimiles, pediformes. Abdomen breve.—G.
Cythere, Miiller. |
Fam. Il. HALOCYPRIDA.— Antenne 2de basi crasse, seepius biramex, ramo longiore 5-7-articulato elongate setigero. Appen- dices mandibulares omnino pediformes, processu molari parvo.
1. CypRIDININzZ.—Pedes quatuor, articulati. Maxille quatuor.—G. Cypridina, EH.
‘ 2. HaLocyprina.—Pedes duo, vermiformes. Maxille sex.—G. Halocypris, D., Conchecia, D.
Lzaro II. PHYLLOPODA.
Trisus I. ARTEMIOIDEA.
Fam. I. ARTEMIADA.—Cephalothorax multiannulatus usque ad caput, testa nusquam tectus. Pedes numerosi, foliacel.
1. CurrocerHaLiInm.—Corpus gracile. Abdomen longum et multiarticulatum. Antenne 2d breves sed pererassee, maris prehensiles.—G. Chirocephalus, Pre-
- a ‘i in en ee re 1 : ae . -
vost, Artemia, Leach. ry 2. Evirmentna.—Abdomen fere obsoletum. Antenne quatuor fere filiformes.— Hl G. Eulimene, Lat. ob Fam. Il. NEBALIADA.—Cephalothorax testa fere bivalvi bene \ | tectus. Abdomen non. inflexum, pauci-annulatum. Pedes plures i posteriores biremes, ac in Cyclopoideis, reliqui anteriores foliacei, 4 branchiales. r G. Nebalia, Leach.
Trrpus II. APODOIDEA.
Fam. APODIDAS.—Oculi duo compositi. Appendices due caudales rigidé setiformes. Testa scutiformis.
G. Apus, Schoeffer. 362
CRUSTACEA.
Taisus II. LIMNADIOIDEA.
Fam. LIMNADIDA. G. Limnadia, Br., Cyzicus, Aud., Limnetis, Loven (Hedessa, Lievin).
Orvo II. CORMOSTOMATA.
Susporpo Il. PAACILOPODA.
Trinus I. ERGASILOIDEA.
Fam. I. MONSTRILLIDA.—Corpus elongatum fere cylindricum. Abdomen 5-6-articulatum, segmentis Imo 2doque appendicibus setosis munitis ac in Setelld. Maxille, antenne postice et pedes antici obsoleti, pedes octo maxime biremes.
G. Monstrilla, D.
Fam. IJ. ERGASILIDA. — Corpus breviusculum, cephalothorace crasso, abdomine stylis caudalibus minutis setigeris confecto. An-
tenns posticee subprehensiles ac in Corycco, pedes octo postici bene biremes.
G. Ergasilus, Nordmann.
Fam. III. NICOTHOIDA).—Frgasilidis affinis. Antenne posticz perbreves vel rudimentarize. [Corpus lobis tumidis prodigiosis late- raliter prolongatum. |
G. Nicothoe, Aud. et Hdw.—[Cujus sedis est Bomolocus, Nordmann ?]
Tripus II. CALIGOIDEA.
Fam. I. ARGULID A.—Corpus late depressum, peltatum. Antenne Ime obsolete. Pedes 1mi tubulati, 2di unguiculati. Ova in tubis vel sacculis externis non gesta.
G. Argulus, Miiller.
Fam. II. CALIGIDA1.—Corpus late depressum, peltatum, segmento
CLASSIFICATION OF CRUSTACEA. 1447
antico pergrandi. Antenne lms breves, 2—3-articulate; 2dee cor- pore tectee. Pedes 1mi graciles, 2di prehensiles vel ancorales. Ova externa in tubis gesta.
1. Garrern2.—Truncus buccalis ovoideus, paulo oblongus, apertura oris inferiore. Maxille ab ore remote, brevissime:, crassee. Tubi ovigeri externi recti. An- tennze antices 2-articulate.—G. Caligus, Miiller, Lepeophtheirus, Nord., Cati- geria, D., Calistes, D., Trebius, Kr.
9. PANDARINE/.—Truncus buccalis acuminatus, apertura terminali. Maxille par- yulee lamellares ad truncum appresse. Tubi ovigeri externi recti——G. Pandarus. Lh., Nogagus, Lh., Phyllophora, H., Dinematura, Lat., Euryhporus, Nord., Lept- dopus, D.
3. Cecropinz.—Pandarinis affines. Tubi ovigeri externi sub abdomine convo-
luti.—G. Cecrops, Lemargus. 4. Sprcrtticina.—Pandarinis affines. Oculi duo ac in Sapphirinis. G. Specdll-
gus, D.
Fam. III. DICHELESTID.4.—Corpus angustum, segmento antico parvo. Antennsx lme breves, 5-10-articulate; 2de fere frontales, ultra caput exserte. Pedes Imi graciles, 2di prehensiles. Ova externa in tubis gesta.
1. DicuELEestin.—Segmenta corporis angusta, non foliosé producta.—G. Dicheles-
tiwm, Herm., Nemesis, Roux. 2. ANTHOSOMATINA.—Segmenta corporis foliosé producta.—G. Anthosoma, Leach.
Trrpus III. LERNAOIDEA.
Fam. I. CHONDRACANTHIDA. — Appendices cephalothoracis
numero quatuor vel plures, unguibus plus minusve ancorales.
1. Srninm.—Antenne anticee et pedes thoracis postici graciles.—G. Selius, Kr.
2. CHONDRACANTHIN#/.—Antenne antics -graciles vel perbreves. Pedes thoracis postici breviter et crasse ancorales.—G. Chondracanthus, de la Roche, Lernanthro- pus, Bl., Lernentoma, Bl., Cycnus, H.
8. CLAVELLINE.—Antenne antics obsolete. Pedes thoracis postici crassi et breves.—G. Clavella, Oken, Peniculus, Nord., dithon, Kr.
Fam. Il. ANCORELLID Ai.—Antenne posticee feminarum ad apicem ssepeque per latera connate et disco ancorali confecte.
1. ANCORELLINE.—Antenne postice feminarum per latera connatze et disco anco- rali confectse.—G. Ancorella, Cuv.
9. LeRNmopopIna”.—Antenne postice feminarum versus apicem connate tantum. —G. Lernzopoda, Kr., Brachiella, Cuv., Achtheres, N., Tracheliastes, N., Basa-
nistes, N.
sear ee es "i —_ ere a ——— Seieniae — : — - Ne EE “ _— ~ we ¥ - - are teeesetone .
i SS eR Se EN PALO TG AO NAOT: AE =,
1448 CRUSTACEA.
Fam. III. PENELLID4.—Pedes obsoleti. Caput 2-4 appendicibus
brevibus non articulatis munitum.
1. Pewetrinz.—Pedes pauci rudimentarii vix obsoleti.—G. Penella, Oken, Ler-
neonema, Edw. 2. LERNEOCERINA.—Pedes omnino obsoleti—G. Lerneocera, Bl., Lernea.
Suzorpo II. ARACHNOPODA vet PYCNOGONOIDEA. Fam. I. NYMPHIDAi.—Antennis munite. 7 G. Nymphum, Fabr., Ammothea, Lh., Pallene, J., Phoxichilidium, J.
Fam. II. PYCNOGONIDA1.—Antennis carentes. G. Pycnogonum, Brunnich, Phoaichilus, Lat.
Supctassis LV. CIRRIPEDIA.
Susctassis V. ROTATORIA.
APPENDIX.
Tur following references are here added to genera of Fossil Crus- tacea, not mentioned in the preceding classification, excluding the Trilobite group.
1. Xanrnms.—Arges of De Haan (Faun. Japon., 21 and 02, pl. 5,
CLASSIFICATION OF CRUSTACEA. 1449
f. 4), a genus near Pilumnus and Menippe. Maxillipeds Cancroid, abdomen in both sexes seven-jointed; lateral margins of carapax parallel and entire, so as to resemble Cyclograpsus Audouinn. Dis- tance between the eyes one-fifth the breadth of the thorax.
Etycea, Leach (Mantell’s Geol. of Sussex, Pl. 29, f. 11, 12), has the transverse form of Xantho.
2. Errpuw (?)—Zanthopsis, M’Coy (Ann. Mag. N. H. [2], iv. 162), approaches Actumnus in nearly orbicular outline and convexity of carapax, but has the fingers acuminated; the basal joint of the outer antennse just reaches the front.
Podopilumnus, M’Coy (loc. cit., p. 165), very near Galene of De Haan. It has the slender legs of our Pilumnus tenellus.
3. AnomourA.—Dromilites and Ogydromites of Edwards; Hela of Count Miinster; Basinotopus and Notopocorystes of M’Coy (Ann. Mag. N. H. [2], iv. 167, 169). The form and sutures of the carapax, in M’Coy’s genera, and the character of the arms and of the posterior legs, are very nearly as in Aglea.
4. THALASSINIDEA.—Magila, Aura, Cancrinos, Orphnea, Brisa, and Brome of Miinster; Megachirus and Pterochirus of Brown.
5. AstactpEA.—Coleia, Broderip (Geol. Trans. [2], v.); Glyphea and Pemphia, von Meyer (Foss. Krebse); Bolina, Miinster; Podlo-
— eratus, Becks; Archeocarabus and Hoploparia of M’Coy (Ann. Mag.
N. H. [2], iv. 173, 175). The species have the transverse suture across the carapax, which distinguishes the Astacidea and most Tha-
lassinidea from the Caridea and Penzeidea.
6. PenmmpnA.—The following genera are referred to the Penzus group by De Haan (Faun. Japon., 187): Antrimpos, Bylgia, Drobna, Dusa, Blaculla, Aiger, Udora, Kolga, Hefriga, Elder of Count Miinster, and possibly, Rawna and Bombur of the same author. In the first seven of these genera all the legs are didactyle, and in Hefriga and Elder all are monodactyle. The genus Saga of Count Miinster, De
Haan refers to the Mysidea.
363
1450 CRUSTACEA.
7. SqurzomEea—Naranda and Reckur of Count Minster are re- ferred here by H. G. Bronn (Index Paleontologicus, ii. 075); and also, with a query, Norna and Urda of the same author. |
8. Isopopa.—Archaoniscus and Palcwoniscus of Edwards (Ann. des Sci. Nat., xx. 326). Archsoniscus, according to Edwards, is between Spheroma and Ancinus.
9. Entomostraca.—T. Rupert Jones adds to the Cytherine the genera (or “subgenera”) Cytherella and Cythereis, based on the form of the shell. Cyprella and Cypridella of Koninck (Descript. An. Foss.) are genera proposed for Cyproid species found in the Belgian carbo- niferous beds; and Dithyrocaris, Scouler (Portlock’s Geol. Rep., Lon- donderry, and Wm. King’s Permian Fossils of England, p. 64, Pale- ontograph. Soc., Pub. 1850), includes Carboniferous or Permian species, which have been referred both to the Cyproidea and Apo- doidea, it being uncertain whether the shell is properly bivalve or not. Cytheropsis, M’Coy, includes Palaeozoic species that have been referred to Cytherina; Beyrichia and Ceratiocaris, M’Coy (Brit. Pal. Fossils, Mus. Camb., 4to, 1851, 135), are genera of other Palaeozoic species. All the carboniferous and Paleozoic species are referred to the section Phyllopoda, near the bivalve genus Limnadia, by Bur- meister and M’Coy. The abnormal number of segments in other Paleozoic Crustacea render it probable that this reference of them is right.
Entomoconchus, M’Coy (Jour. Geol. Soc. Dublin, ii.), and Daph- noidea, Hibbert (On the Burdie House Limestone, Trans. Roy. Soc. Edinb., xiii. 180), are other related genera. The latter may be near A pus.
Eurypterus, Harlan, and Pterygotus, M’Coy, are other Paleozoic genera, probably of Entomostraca. Eurypterus has been supposed to be related to Limulus.
Belinurus, Koninck, Halicyne, von Meyer, are other genera, referred to the Poecilopoda.
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ON THE
GEOGRAPHICAL DISTRIBUTION
OF
CRUSTACEA.
I. PRELIMINARY CONSIDERATIONS ON THE TEMPERATURE OF THE OCEANS.
Tue temperature of the waters is well known to be one of the most influential causes limiting the distribution of marine species of life. Before therefore we can make any intelligent comparison of the Crus- tacea of different regions, it is necessary to have some clear idea of the distribution of temperature in the surface waters of the several oceans; and, if we could add also, the results of observations at
various depths beneath the surface, it would enable us still more per- —
fectly to comprehend the subject. The surface temperature has of late years been quite extensively ascertained, and the lines of equal temperature may be drawn with considerable accuracy. But in the latter branch of thermometric investigation almost everything yet remains to be done: there are scattering observations, but none of a systematic character, followed through each season of the year.
The Map which we have introduced in illustration of this subject,
presents a series of lines of equal surface temperature of the oceans. |
The lines are isocheimal lines, or, more properly, isocrymal lines; and where they pass, each exhibits the mean temperature of the waters along its course for the coldest thirty consecutive days of the year.
a ccmmneee teas SS
1452 CRUSTACEA.
The line for 68° F., for example, passes through the ocean where 68° F., is the mean temperature for extreme cold weather. January is not always the coldest winter month in this climate, neither is the winter the coldest season in all parts of the globe, especially near the equator. On this account, we do not restrict the lines to a given month, but make them more correctly the limit of the extreme cold for the year at the place.* Between the line of 74° north and 74° south of the equator, the waters do not fall for any one month below 74° F.; between 68° north and south, they do not fall below 68°. There are several reasons why isocrymal are preferable to summer or isotheral lines. The cause which limits the distribution of species northward or southward from the equator is the cold of winter, rather than the heat of summer, or even the mean temperature of the year. The mean temperature may be the same when the extremes are very widely different. When these extremes are little remote, the equable character of the seasons, and especially the mildness of the winter temperature, will favour the growth of species that would be altogether cut off by the cold winters where the extremes are more intense. On this account, lines of the greatest cold are highly impor- tant for a chart illustrating the geographical distributions of species, whether of plants or animals. At the same time, summer lines have their value. But this is true more particularly for species of the land, and fresh-water streams, and sea-shore plants. When the sum- mer of a continent is excessive in its warmth, as in North America, many species extend far from the tropics that would otherwise be confined within lower latitudes. But in the ocean, the extremest cold in the waters, even in the Polar regions, wherever they are not solid ice (and only in such places are marine species found), is but a few degrees below 32° Fahrenheit. The whole range of temperature for a given region is consequently small. The region which has 68° F. for its winter temperature, has about 80° for the hottest month of summer; and the line of 56° F. in the Atlantic, which has the lati- tudes of the state of New York, follows the same course nearly as the
* The word dsocrymal here introduced is from the Greek ios, equal, and xguros, extreme cold, and applies with sufficient precision to the line for which it is used. These lines are not isocheimal lines, as these follow the mean winter temperature ; and to use this term in the case before us, would be giving the word a signification which does not belong to it, and making confusion in the science.
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1458
summer line of 70° F. In each of these cases the whole extent of the range is small, being twelve to fourteen degrees.*
In fresh-water streams, the waters, where not frozen, do not sink lower than in the colder oceans, reaching at most but a few degrees below freezing. Yet the extremes are ereater than for the ocean ; for in the same latitudes which give for the ocean 56° and 70° F. as the
limits, the land streams of America range in temperature between 30° —
and 80° F., and the summer warmth in such a case, may admit of the development of species that would otherwise be excluded from the
region.
While then both isocrymal and isothermal lines are of importance on charts illustrating distribution over the continents, the former are
pre-eminently important where the geography of marine species is to
be studied. The lines of greatest cold are preferable for marine species to those
of summer heat, also because of the fact that the summer range for 30° of latitude either side of the equator is exceedingly small, being put three to four degrees in the Atlantic, and six to eight degrees in the Pacific. The July isothermal for 80° F. passes near the paral- lel of 30°; and the extreme heat of the equatorial part of the Atlantic Ocean is rarely above 84°. The difficulty of dividing this space by convenient isothermals with so small a range is obvious.
It is also an objection to using the isotheres, that those towards the equator are much more irregular in course than the isocrymes. That of 80° for July, for example, which is given on our Map from Maury’s Chart, has a very flexuous course. Moreover, the spaces between the isotheres fail to correspond as well with actual facts in geographical distribution. 'The courses of the cold water currents are less evident on such a chart, since the warm waters in summer to a great extent
overlie the colder currents. It is also to be noted that nothing would be gained by making the
mean temperature for the year, instead of the extremes, the basis for laying down these lines, as will be inferred from the remarks already made, and from an examination of the chart itself.
The distribution of marine life is a subject of far greater simplicity
* Moreover, the greatest range for all oceans is but 62° of Fahrenheit, the highest being 88°, and the lowest 26°; while the temperature of the atmosphere of the globe
hag a range exceeding 150°.
364
eee ence tet:
eee
1454 CRUSTACEA.
than that of continental life. Besides the influence on the latter of summer temperature in connexion with that of the cold seasons, already alluded to, the following elements or conditions have to be considered :—the character of the climate, whether wet or dry ;—of the surface of the region, whether sandy, fertile, marshy, etc.;—of the vegetation, whether that of dense forests, or open pasture-land, ete. ;— of the level of the country, whether low, or elevated, etc. These and many other considerations come in, to influence the distribution of land species, and lead to a subdivision of the Regions into many sub- ordinate Districts. In oceanic productions, depth and kind of bottom have an important bearing: but there is no occasion to consider the moisture or dryness of the climate; and the influence of the other peculiarities of region mentioned is much less potent than with conti- nental life.
We would add here, that the data for the construction of ia chart have been gathered, as regards the North Atlantic, from the iso- thermal chart of Lieutenant Maury, in which a vast amount of facts are registered, the result of great labour and study. For the rest of the Atlantic and the other oceans we have employed the Meteoro- logical volume of Captain Wilkes of the Exploring Expedition Reports, which embraces observations in all the oceans and valuable deductions therefrom; also, the records of other travellers, as Humboldt, Duper- rey of the Coquille, D'Urville of the Astrolabe, Kotzebue, Beechey, Fitzroy, Vaillant of the Bonite, Ross in his Antarctic Voyage, toge- ther with such isolated tables as have been met with in different Journals. The lines we have laid down, are not however, those of any chart previously constructed, for the reason stated, that they mark the positions where a given temperature is the mean of the coldest month (or coldest thirty consecutive days) of the year, instead of those where this temperature is the mean annual or monthly heat; and hence, the apparent discrepancies, which may be observed, on comparing it with isothermal charts.
The isocrymal lines adopted for the chart are those of 80°, 74°, 68°, 62°, 56°, 50°, 44°, and 35° of Fahrenheit. They diminish by 6°, excepting the last, which is 9° less than 44°.
In adopting these lines in preference to those of other degrees of _ temperature, we have been guided, in the first place, by the great fact, that the isocryme of 68° is the boundary line of the coral-reef seas, as
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1455
explained by the author in his Report on Zoophytes.* Beyond this line either side of the equator, we have no species of true Madrepora, Astrea, Meandrina or Porites; below this line, these corals abound ) and form extensive reefs. This line is hence an important starting point in any map illustrating the geography of marine life. Passing
beyond the regions of coral reefs, we leave behind large numbers of Mollusca and Radiata, and the boundary marks an abrupt transition in zoological geography.
The next line below that of 68° F., is that of 74° F. The corals of the Hawaiian Islands, and the Mollusca also to a considerable extent, differ somewhat strikingly from those of the Feejees. The species of Astrea and Meandrina are fewer, and those of Porites and Pocillopora more abundant, or at least constitute a much larger pro- portion of the reef material. These genera of corals include the hardier species; for where they occur in the equatorial regions they are found to experience the greatest range in the condition of purity of the waters, and also the longest exposures out of water. Their abundance at the Hawaiian Islands, as at Oahu, is hence a conse- quence of their hardier character, and not a mere region peculiarity independent of temperature. There are grounds, therefore, for draw- ing a line between the Hawaiian Islands and the Feejees; and as the temperature at the latter sinks to 742° I’. some parts of the year, 74° F. is taken as the limiting temperature. The Feejee seas are exceed- ingly prolific and varied in tropical species. The corals grow in great ni luxuriance, exceeding in extent and beauty anything elsewhere ob- a
served by the writer in the tropics. The ocean between 74° F., north )
of the equator, and 74° F. south, is therefore the proper tropical or |
torrid region of zoological life. ’ With respect to the line of 80° F., we are not satisfied that it is of t |
much importance as regards the distribution of species. The range {
from the hottest waters of the ocean 88° to 74° F.is but fourteen it degrees, and there are probably few species occurring within the region ii that demand a less range. Still, investigations hereafter made, may |
show that the hot waters limited by the isocryme of 80° includes some peculiar species. At Sydney Island and Fakaato, within this it hot area, there appeared to be among corals a rather greater preva- i lence than usual of the genus Manopora, which as these are tender te
* In the author’s Report on Geology, 66° F. is set down as the limiting temperature of Coral-reef Seas: this, however, is given as the extreme cold. 68° appears to be the mean of the coldest month, and is therefore here used.
1456 CRUSTACEA.
species, may perhaps show that the waters are less favourable for hardier corals than those of the Feejees, where the range of tempera- ture is from 74° to 80° F.; but this would be a hasty conclusion, with- out more extended observations. The author was on these islands only for a few hours, and his collections were afterwards lost at the wreck of the Peacock, just as the vessel was terminating the voyage by entering the Columbia River. _
It is unnecessary to remark particularly upon the fitness of the other isocrymals for the purposes of illustrating the geographical dis- tribution of marine species, as this will become apparent from the explanations on the following pages.
The regions thus bounded require, for convenience of designation, separate names, and the following are therefore proposed. They constitute three larger groups: the jirst, the Torrid zone or Coral-reef seas, including all below the isocryme of 68° F.; the second, the Temperate zone of the oceans, or the surface between the isocrymes of 68° F. and 35° F.; the third, the Frigid zone, or the waters beyond
the isocryme of 36° F.
I. TORRID OR CORAL-REEF ZONE.
Regions. Isocrymal limits. . Supertorrid, . : : : : . 80° F. to 80° F.
«Porridss <3 ; : : : . 80° to 74° . Subtorrid, F ; ; : ; 97 PEE 3. $0 B89
II. TEMPERATE ZONE.
. Warm Temperate, ‘ . Temperate,
. Subtemperate,
. Cold Temperate,
. Subfrigid,
iI. FRIGID ZONE. 1. Frigid, ; . 85° to 26° A ninth region—called the Polar—may be added, if it should be
found that the distribution of species living in the Frigid zone re- quires it. There are organisms that occur in the ice and snow itself
a
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1457
of the polar regions; but these should be classed with the animals of the continents; and the continental isotherms or isocrymes, rather than the oceanic, are required for elucidating their distribution.
It seems necessary to state here the authorities for some of the more important positions in these lines, and we therefore run over the observations, mentioning a few of most interest. There is less necessity for many particulars with reference to the North Atlantic, as our facts are mainly derived from Lieut. Maury’s Chart, to which the author would refer his readers.
1. Nortu ATLAntic.—lsocryme of 74° F.—This isocryme passes near
the reefs of Key West, and terminates at the northeast cape of Yu- catan; it rises into a narrow flexure parallel with Florida along the Gulf Stream, and then continues on between the Little and Great Bahamas. To the eastward, near the African coast, it has a flexure northward, arising from the hot waters along the coast of Guinea, which reach in a slight current upward towards the Cape Verde Islands. The line passes to the south of these islands, at which group, Fitzroy, in January of 1852, found the sea-temperatures 71° and 72° FE. : Isocryme of 68° F.—Cape Canaveral, in latitude 27° 30’, just north of the limit of coral reefs on the east coast of Florida, is the western termination of the line of 68°. The Gulf Stream occasions a bend in this line to 36° north, and the polar current, east of it, throws it southward again as far as 29° north. Westward it inclines much to the south, and terminates just south of Cape Verde, the eastern cape of Africa. Sabine found a temperature of 64° to 65° F. off Goree, below Cape Verde, January, 1822; and on February 9, 1822, he obtained 664° near the Bissao shoals. These temperatures of the cold season contrast strikingly‘with those of the warm season. Even in May (1831), Beechey had a temperature of 86° off the mouth of Rio Grande, between the parallels of 11° and 12° north.
Tsocryme of 62° F.—This isocryme leaves the American coast at Cape Hatteras, in latitude 354° north, where a bend in the outline of the continent prevents the southward extension of the polar currents from flowing close along the shores. It passes near Madeira, and bends southward reaching Africa nearly in the latitude of the Canaries.
Tsocrymes of 56° and 50° F.—Cape Hatteras, for a like reason, is
the limit of the isocrymes of 56° and 90° as well as of 62°, there being 365
fing incase ent OMI CE et a EIA a A
1458 CRUSTACEA.
no interval between them on the American coast. The line of 56° F. has a deep northward flexure between the meridians of 35° and 40° west, arising from the waters of the Gulf Stream, which here (after a previous east and west course, occasioned by the Newfound- land Bank, and the Polar Current with its icebergs) bends again northeastward, besides continuing in part eastward. The Polar Current sometimes causes a narrow reversed flexure, just to the east of the Gulf Stream flexure. Towards Europe, the line bends southward, and passes to the southwest cape of Portugal, Cape St. Vincent, or, perhaps to the north cape of the Straits of Gibraltar. Vaillant, in the Bonite, found the temperature at Cadiz in February, 492° to 56° F. (9:7° to 134° C.), which would indicate that Cadiz, although so far south (and within sixty miles of Gibraltar), experiences at least as low a mean temperature as 56° F. for a month or more of the winter season. We have, however, drawn the line to Cape St. Vincent, which is in nearly the same latitude. Between Toulon and Cadiz, the tem- perature of the Mediterranean in February, according to Vaillant, was 554° to 604° F. (13°1° to 15°7° C.), and it is probable, therefore, that Gibraltar and the portion of the Mediterranean Sea east and north to Marseilles, fall within the Zemperate Region, between the isocrymes of 56° and 62° F., while the portion beyond Sardinia and the coast by Algiers is in the Warm Temperate Region, between the isocrymes of 62° and 68° F. 7
The line of 50° F., through the middle of the ocean, has the lati- tude nearly of the southern cape at the entrance of the British Chan- nel; but approaching Europe it bends downward to the coast of Portugal. The low temperature of 493° observed by Vaillant at Cadiz would carry it almost to this port, if this were the mean sea- temperature of a month, instead of an extreme within the bay. The line appears to terminate near latitude 42°, or six degrees north of the isocryme of 56°. This allows for a diminution of a degree Fahrenheit of temperature for a degree of latitude. A temperature as low as 61° F. has been observed at several points within five degrees of this coast in July, and a temperature of 52° F., in February. Vigo Bay, just north of 42° north, lies with its entrance opening westward, well calculated to receive the colder waters from the north; and at this place, according to Mr. R. Mac Andrew,* who made several dredgings with reference to the geographical distribution of species, the Mollusca
* Rep. Brit. Assoc., 1850, p. 264.
en emetieaaaiactitac anny ND TC OO NTIS a — ar RE han aN AE apy satiate hee alll 2 neem 5 = one penne =" - —— 2 oa = F ae Ce e ee
‘one ngewe
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1459
have the character rather of those of the British Channel than of the Mediterranean.
Tsocryme of 44° F.—This line commences on the west, at Cape Cod, where there is a remarkable transition in species, and a natural boundary between the south and the north. The cold waters from the north and the ice of the Newfoundland Banks, press the line close upon those of 50° and 56° F. But after getting beyond these in- fluences, it rapidly rises to the north, owing to the expansion of the Gulf Stream in that direction, and forms a large fold between Britain and Iceland; it then bends south again and curves around to the west coast of Ireland.
Isocryme of 85° F.—This line has a bend between Norway and Ice- land like that of 44°, and from the same cause,—the influence of the Gulf Stream. But its exact position in this part has not been ascer-
tained.
9. Sours AtLantic.—Isocryme of 74° F.—This line begins just south of Bahia, where Fitzroy found in August (the last winter month) a temperature of 74° to 753° F. During the same month he had 753° to 764° F. at Pernambuco, five degrees to the north. Off Bahia, the temperature was two degrees warmer than near the coast, owing to the warm tropical current, which bends the isocryme south to latitude 17° and 18°, and the cold waters that come up the coast from the south. The line gradually rises northward, as it goes west, and passes the equator on the meridian of Greenwich. Sabine, in a route nearly straight from Ascension Island, in 8° south, to the African coast under the equator, obtained in June (not the coldest winter month) the temperatures 78°, 19°, 1485 TAR, 120° 18 Ane temperature thus diminishing on approaching the coast, although at the same time nearing the equator, and finally reaching it within a few miles. These observations in June show that the isocryme of 74° FB. passes north of the equator. The temperatures mentioned in Maury’s Chart afford the same conclusion, and lead to its position as laid down.
Tsocryme of 68° F.—On October 23d to 25th, 1834, Mr. D. J. Browne, on board the U. 8. Ship Erie, found the temperature of the sea on entering the harbour of Rio Janeiro, 672° to 682° F. Fitzroy, on July 6, left the harbour with the sea-temperature 702° F. Beechey, in August, 1825, obtained the temperatures 68°16° to 69°66° F. off the harbour. The isocryme of 68° F. commences therefore near Rio, not far south of this harbour. Eastward of the harbour, the tem-
— a : : — tenn ea an ee ae . ers Se
ee cet acme
1460 CRUSTACEA.
perature increases two to four degrees. In July, Fitzroy carried a temperature above 68° as far south as 33° 16’ south, longitude 50° 10’ west, the water giving at this time 682° to 693° F. Beechey in August obtained 68° F. in 31° south, 46° west. The isocryme of 68° F. thus bends far south, reaching at least the parallel of 30°. It takes a course nearly parallel with the line of 74° F., as different observations show, and passing just south of St. Helena, reaches the African coast, near latitude 7° south. Fitzroy, on July 10 (mid-winter), had a sea- temperature of 684° near St. Helena; and Vaillant, in the Bonite, in September found the sea-temperature 68°7° to 69°26° F.
Tsocrymes of 56° and 50° F.—These two isocrymes leave the American coast rather nearly together. The former commences just north of the entrance of the La Plata. Fitzroy, in July 23 to 31, 1832, found the sea-temperature at Montevideo 56° to 58° F., and in August, 57° to 544° F. These observations would lead to 56° F. as nearly the mean of the coldest month. The temperature 56° F. was also ob- served in 35° south, 53° west, and at 36° south, 56° 36’ west. But on July 10 and 18, 1833, at Montevideo, the sea-temperature was 464° to 474°, a degree of cold which, although only occasional, throws the line of 56° F. to the north of this place. The temperature near the land is several degrees of Fahrenheit lower than at sea three to eight degrees distant. East of the mouth of the La Plata, near longitude 50° west, Beechey, in July, 1828, found the temperature of the sea 61-86° F. So in April 23 to 29, Vaillant obtained the temperature 59°5° to 61-:25° F. at Montevideo, while in 35° 5’ south, 49° 23’ west, on April 14, it was 66°2° F., and farther south, in 87° 42’ south, 53° 28’ west, April 30, it was 644° F.; and in 39° 19’ south, 54° 32’ west, on May 1, it was 572° F.; but a little to the westward, on May 2, in 40° 30/ south, 56° 54’ west, the temperature was 48° F., an abrupt transition to the colder shore waters. Beechey, in 39° 31’ south, 45° 13’ west, on August 28 (last of winter), found the temperature 57:20° F., and on the 29th, in 40° 27’ south, 45° 46’ west, it was 54:20°; while on the next day, in 42° 27’ south, and 45° 11’ west, the temperature fell to 47-83° F. These and other observations serve to fix the position of the isocryme of 56° F. It approaches the African coast, in 32° south, but bends upward, owing to cold waters near the land. On August 20, Vaillant, in 83° 43’ south, 15° 51’ east, found the tempe- rature 56° F.; while on the 22d, in the same latitude, and 14° 61’ east (or one degree farther to the westward), the temperature was 57-74° F., being nearly two degrees warmer. At Cape Town, in June
Sei Oana eA AOE AAI = CA ET ATO SE eth eee tee ee a ; a Sa a =— A ON 7 stig i i sictll
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1461
(latitude 34°), Fitzroy found 55° to 61° F., while on August 16, farther south, in 35° 4’ south, and 15° 40° west, one hundred and fifty miles from the Cape, Vaillant found the temperature 59°36° F. The high temperature of the last is due to the warm waters that come from the Indian Ocean, and which afford 61° to 64° F. in August, off the south extremity of Africa, west of the meridian of Cape Town.
The isocryme of 50° F. leaves the American coast just south of the La Plata; after bending southwardly to the parallel of 41°, it passes east nearly parallel with the line of 56° F. It does not reach the African coast.
Tsocrymes of 44° and 35° F.—Fitzroy in August (the last winter month) of 1833, found the sea-temperature at Rio Negro (latitude 41° south) 484° to 50° F. But during the voyage from the La Plata to Rio Negro, a few days before, a temperature of 443° to 46° was met with; this was in the same month in which the low temperature men- tioned on a preceding page was found at Montevideo. The bend in the coast north of the entrance to the La Plata, is to some extent, a limit between the warmer waters of the north and the colder waters from the south; not an impassable limit, but one which 1s marked often by a more abrupt transition than occurs elsewhere along this . part of the coast. The water was generally three or four degrees colder at Montevideo, than at Maldonado, the latter port being hardly sheltered from the influence of the tropical waters, while Montevideo is wholly so. The exact point where the line of 44° F. reaches the coast is somewhat uncertain, yet the fact of its being south of Rio Negro is obvious. After leaving the coast, it passes north of 473° south, in longitude 53° west, where Beechey, in July, 1828, found the sea-temperature 40°70° F.
The line of 35° F. through the middle of the South Atlantic, follows
nearly the parallel of 50°; but towards South America it bends south-
ward and passes south of the Falklands and Fuegia. At the Falklands, Captain Ross, in 1842, found the mean temperature of the sea for
July, 38°73°, and for August, 38-10°; while in the middle of the At-_
lantic, on March 24, latitude 52° 31’ south, and longitude 8° 8’ east, the temperature was down to 34:3° F., and in 50° 18’ south, 7° 10’ east, it was 87° F.; March 20, in 54° 7’ south, on the meridian of Green- wich, it was 33:4° F. The month of March would not give the cold- The temperature of the sea along the south coasts
est temperature. 366
~~ .
Seems erenteae PE sic.
= .k j mee
1462 CRUSTACEA.
of Fuegia sinks nearly to 35°, if not quite, and the line of 35° there- fore runs very near Cape Horn, if not actually touching upon Fuegia.
Norra Paciric Ocran.—Jbocryme of 80° F.—The waters of the At- lantic in the warmest regions, sink below 80° F. in the colder season, and there is therefore no proper Supertorrid Region in that ocean. In the Gulf of Mexico, where the heat rises at times to 80° F’,, it sinks in other seasons to 74° and in some parts, even to 72° F.; and along the Thermal equator across the ocean, the temperature is in some portions of the year 78°, and in many places TAS.
But in the Pacific, where the temperature of the waters rises in some places to 88° F., there is a small region in which through all seasons, the heat is never below 80°. It is a narrow area, extending from 165° east to 148° west, and from 73° north to 11° south. In going from the Feejees in August, and crossing between the meridians of 170° west and 180°, the temperature of the waters, according to Captain Wilkes, increased from 79° to 84° F., the last temperature being met with in latitude 5° south, longitude 175° west, and from this, going northward, there was a slow decrease of temperature. The Ship Relief, of the Expedition, in October, found nearly the same temperature (833°) in the same latitude and longitude 177° west.* But the Peacock, in January and February (summer months), found the sea-temperature 85° to 88° F., near Fakaafo, in latitude 10° south, and longitude 171° west. In latitude 5° south and the same longi- tude, on the 16th of January, the temperature was 84°; in 3° south, January 10th, it was 83° F.; on March 26th, in 5° south, and longi- tude 175° east, the temperature was 86° F.; on April 10th, in the same longitude, under the equator, at the Kingsmills, the temperature was 833° F.; on May 2d, at 5° north, longitude 174° east, 834° F.; May 5th, latitude 10°, longitude 169° east, 82° F. The fact that the region of greatest heat in the Middle Pacific is south of the equator, as it has been laid down by different authors, is thus evident; the limits of a circumscribed region of hot waters in this part of the Pacific, were first drawn out by Captain Wilkes.
Another Supertorrid region may exist in the Indian Ocean, about its northwestern portion; but we have not sufficient information for laying down its limits.
Isocryme of 74° F.—At San Blas, on the coast of Mexico, Beechey
* See, for these facts, Captain Wilkes’s Report on.the Meteorology of the Expedition.
*
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1463
found the mean temperature of the sea for December, 1827, 74:63°
F.; for January, 73°69° F.; for February, 72°40° F. The line of 74°
F. commences therefore a degree or two south of San Blas. In the
winter of 1827 on January 16 to 18, the temperature of 74°3° to
74:6° F. was found by Beechey, in 16° 4’ to 16° 15’ north, 132°
40’ to 135° west; and farther west, in the same latitude, longitude
141° 58’ west, the temperature was 74°83° F. West of the Sandwich
Islands, near the parallel of 20° north, the temperature rises five degrees
| in passing from the meridian of 165° west to 150° east, and the iso- is cryme of 74° F., consequently rises somewhat to the north, over this part of the ocean. Between the meridians of 130° and 140° east, the
temperature of the sea is quite uniform, indicating no northward flexure ;
and west of 130° east, nearing China, there is a rapid decrease of tem-
perature, bending the line far south. Vaillant, of the Bonite, found
the sea off Cochin China, in latitude 12° 16’ north, 109° 28’ east, ©
to have the temperature 74:12° F.; and even at Singapore, almost under the equator, the temperature on February 17 to 21, was 77-54° to 79°34° F. The isocryme of 74° F. terminates therefore upon the southeastern coast of Cochin China.
Isocryme of 68°.—Off the Gulf of California, in 25° north, 117° west, Beechey obtained for the temperature of the sea, on December 13, 65° F.; on December 15, in 23° 28’ north (same latitude with the extremity of the peninsula of California), 115° west, a temperature of 69-41° F. The line of 68° will pass from the extremity of this penin- sula, the temperature of the coast below, as it is shut off mostly from the more northern and colder waters, being much warmer. The tem- perature 69-41° in the middle of December, is probably two and a half degrees above the cold of the coldest month, judging from the relative temperatures of the latter half of December and the month of February at San Blas. Leaving California, the isocryme of 68° will therefore bend a little southerly to 224°, in longitude 115° west. In 23° 56’ north, 128° 33’ west, Beechey, on January 11, found the
temperature of the sea 67°83° F. The line of 68° passes north of the Sandwich Islands. The mean temperature of the sea at Oahu in February, 1827, was 69°69° F.
Near China, this isocryme is bent far south. At Macao, in winter, Vaillant found the sea-temperature, on January 4, 59° F.; on January 5 to 10, 52°7° to 50° F.; January 11, 12, 49°87° to 48-74° F.; January
13 to 16, 50°9° to 52°16° F.; and at Touranne in Cochin China, on February 6 to 24, the sea-temperature was 68° to 682° F.; in 16° 22'
te ar =
1464 CRUSTACEA,
north, 108° 11’ east, on January 24, it was 67°; in 12° 16’ north, 109° 28’ east, it was 74:12° F. The very low Macao temperature is that of the surface of the Bay itself, due to the cold of the land, and not probably, as the other observations show, of the sea outside.
The line, before passing south, bends northward to the southeast shore of Niphon, which is far warmer than the southeast coast, along Kiusiu. In the Report of the Morrisons’ visit to J eddo (Chinese Repository for 1837), a coral bottom is spoken of, as having been encountered in the harbour of Jeddo. According to Siebold (Crust. Faun. Japon., p. ix.), the mean winter temperature (air) of Jeddo is 57° F., while that of Nagasaki, although farther south, is 44° F..
Isocryme of 62° F.—On January 8, 1827, Beechey found in 29° 42’ north; 126° 387’ west, the temperature 62°75° F.; while on the pre- ceding day, 32° 42’ north, 125° 43’ west, the sea-temperature was 60:5° F. Again, on December 11, in 29° north, 120° west, the tem- perature was 62°58° F.
Isocryme of 56° F.—At Monterey, on January 1 to 5, the sea-tem- perature according to Beechey was 56°; but the mean temperature of the sea for November 1 to 17, was 54°91°. In the Yellow Sea, the January temperature is 50° to 56° F’., and the line of 56° begins south of Chusan.
Tsocryme of 50° F.—At San Francisco, from November 18 to De- cember 5, 1826, Beechey found the mean sea-temperature to be 51:14° F., and off Monterey, in longitude 123° west, the temperature was 50:°75° F., on December 6. But in December of 1826, the mean sea- temperature at San Francisco was 54°78° F.; and for November, 60:16° F. The line of 50° F. (mean of the coldest thirty consecutive days), probably leaves the coast at Cape Mendocino.
Tsocrymes of 44° and 35° F.—Captain Wilkes found the temperature off the mouth of the Columbia River, through ten degrees of longitude, 48° to 49° F., during the last of April, 1841. The isocryme of 44° would probably reach the coast not far north of this place. The tem- perature on October 21, in the same latitude, but farther west, 147° west, was 52°08° F. On October 16, in 50° north, 169° west, the temperature was 44°91° F. According to some oceanic temperatures for the North Pacific, obtained from Lieutenant Maury, the sea-tempe- rature off northern Niphon, in 41° north and 1423° east, was 44° F.,in © March, showing the influence of the cold Polar current; and in 42° north, and 149° east, it was 43° F. The line of 44° hence bends southward as far as latitude 40° north, on the Japan coast.
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1465
- Again, in March, in 43° 50’ north, 151° east, the sea-temperature was 41° F.; in 44° 50’ north, 152° 10’ east, 89° F'.; in 46° 20’ north, 156° east, 33° F.; in 49° north, 157° east, 33° F.; and at the same time, west of Kamschatka, in 90° north, 153° east, 88° F.; in 55° 40’ north, 153° west, 38° F. The line of 35° consequently makes a deep bend, nearly to 45° north, along the Kurile Islands.
Sour Pactric.—Isocrymes of 74°, 68°, and 62° F.—The tempera- ture of the sea at Guayaquil, on August 3d, was found by Vaillant, to be, in the river, from 702° to 732° F., and at the Puna anchorage, August 5 to 12, 74°7° to 752° F. But off the coast, August 15, in 9° 22’ south, 81° 42’ west, the temperature was 69:8° F.; and the next day, in 1° 25’ south, 84° 12’ west, it was 70° F.; on the 17th, 1° south, 87° 42/ west, it was 71:28° F.; and on the 14th, nearer the shore of Guayaquil, in 8° 18’ south, 80° 28’ west, it was 78° F. Again, at Payta, one hundred miles south of Guayaquil, in 5° south, the sea-temperature was found by Vaillant, July 26 to 31, to be 60°8° to 614° F. The isocryme of 74° F., consequently, leaves the coast just north of the bay of Guayaquil, while those of 68° and 62° F., both commence between Guayaquil and Payta. Payta is situated so far out
on the western cape of South America that it receives the cold waters —
of the south, while Guayaquil is beyond Cape Blanco, and protected by it from a southern current. At the Gallapagos, Fitzroy found the tem- perature as low as 682° F. on the 29th of September, and the mean for the day was 62°. The average for September was, however, nearer 66°. The Gallapagos appear, therefore, to lie in the Warm Temperate Region, between the isocrymes of 62° and 68° F. Fitzroy, in going from Callao to the Gallapagos, early in September, left a sea-tempe- rature of 57° F. at Callao, passed 62° F. in 9° 58’ north, and 79° 42? west, and on the 15th, found 684° F. off Barrington Island, one of the Gallapagos. A
In the warm season, the cold waters about the Gallapagos have narrow limits; Beechey found a sea-temperature of 83:58° on the 30th of March, 1827, just south of the equator, in 100° west. But in October, Fitzroy, going westward and southward from the Gallapagos, found a sea-temperature of 66° F. at the same place; and in a nearly straight course from this point to 10° south, 120° west, found the sea- temperatures successively, 68°, 70°, 100", 120", 39", 14°; and beyond this, 754°, 764°, 772° F., the last on November 8, in 14° 24!
367
1466 CRUSTACEA.
south, 136° 51’ west. These observations give a wide sweep to the cold waters of the colder seasons, and throw the isocrymes of 74° and 68° F., far west of the Gallapagos. Captain Wilkes, in passing directly west from Callao, found a temperature of 68° F., in longitude 85° west; 70° F., in 95° west; and 74° F., in 102° to 108° west. These and other observations lead to the positions of the isocrymes of 74°, 68°, and 62°, given on the Chart. The line of 74° passes close by Tahiti and Tongatabu, and crossing New Caledonia, reaches Australia in latitude 25° S. In mid-ocean there is a bend in all the southern isocrymes.*
* The following observations by Mr. W. C. Cunningham (in connexion with those of other navigators), establish the fact of this flexure; they were sent by him to the author, in a letter, dated Talcahuano, Chili.
s
1. FROM THE HARBOUR OF APIA, ISLAND OF UPOLU, TO TAHITI.
LATITUDE, LONGITUDE. WEATHER.
Fine. Showery.
May 11 15°02’ §. £ « heavy rains.
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CEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1467
Isocrymes of 56° and 50° F.—The temperature at Callao, in July, averages 584° or 59° F. At Iquique, near 20° south, Fitzroy had 58° to 60° F., on July 14, 1835; and off Copiapo, in the same month, 564° F. At Valparaiso, Captain Wilkes found a sea-temperature of 52%° B., in May; and Fitzroy, in September, occasionally obtained 48° F., but generally 52° to 53°. Off Chiloe, Fitzroy found the tem- perature 48° to 512° in July.
2. FROM TAHITI TO VALPARAISO.
DATE. LATITUDE. | LONGITUDE. WINDS. SEA.* AIR.™ REMARKS. Aug. 26 USOT’ 61°20" S.E. 738° 76° Fine 27 20 10 151 33 8.H. 72 75 Clear 28 22 02 152 06 8.E. 72 75 # 29 22A8 152 45 S.E. 75 73 § 30 22 30 151 38 Var. 76 72 e 31 23 15 152 47 S.E. 68 72 3 Sept. 1 24 24 152 51 S.S.E. 68 72 ee 2 25 14 152 12 N.N.E. 69 72 Cloudy. 3 96°18 151 41 Sos 69 70 Clear. a 27 18 150 47 S.W. 65 66 Fine. 5 28 46 149 49 S.W. 63 68 Clear. 6 28 40 149 49 S.W. 62 66 s tf 29 21 150 21 WwW. 61 65 Rains. 8 30 19 151 40 §.E. 60 65 Cloudy. 9 31 30 152 43 S.E. 58 60 Squally; dark. 10 82 30 152 46 8.E. 58 60 a ba Ast: 83 45 151 56 Var. 58 57% Cloudy. 12 34 42 150 27 Var. 56 58 Thick and cloudy. 18 385 43 148 53 N.E. 56 56 Cloudy. 14 36 50 147 15 N.E 56 56 Clear. 15 38 19 146 37 Var. 55s 55 Cloudy. 16 39 23 145 38 N.N.E. 53 52 es 17 40 18 148 43 N.E. 50 61 Rain; dark. 18 40 01 141 19 N.E. 62 52 “ gqually. 19 89 05 1589 1: N.N.E. 55 54 Clear. 20 88 24 126 58 N. by W. 56 55 Foggy. 21 38 09 134 08 N.N.W. 56 54 vs 22 87 42 130 388 N.N.E. 56 65 Cloudy. 23 87 23 127 22 N.N.W. 55 54 Rains. 24 86 52 124 06 N.N.W. 56 54 6 25 87 05 121 00 N.W. 58 57 Clear. 26 87 05 117 32 W. 56 55 6 27 Sve 114 18 N.W. 56 54 Squally. 28 37 08 112 19 Var. 58 67 x 29 36 47 108 58 N.W. 57 55 Cloudy. 30 86 48 106 31 W. 57 55 oa mild. Oct. 1 36 29 104 12 Var. 58 57 Squally. 86 22 103 30 Var. 55 56 si 3 86 42 101 00 N.N.W. 58 56 Cloudy. 4 oh ae 97 06 N.W. 58 57 “ 5 86 58 94 30 W.N.W. 58 56 es 6 sue yl 90 20 W.N.W. 56 54 Clear. fg 36 18 88 11 W.N.W. 57 55 a 8 35 28 84 55 N.W. 56 56 = 9 34 14 82 08 N.W. 54 56 2 10 34 06 74 25 Var. 57 57 oo 11 84 03 73 06 S.wW. SVE 56 Fine. 12 84 48 72 10 N.N.E. 57 57 + 13 83 39 72 40 N. 56 57 * 14 83 33 72 50 N.W. 56 57 « 15 83 10 72 04 8 56 56 “ 16 55 54 os At Valparaiso. * Mean temperature. — ee . i lan 2 a on a Ee i aaa aes aad 5 a
1468 | CRUSTACEA.
Inpran Ocean.—Jsocrymes of 74° and 68° F.—Off the south extre- mity of Madagascar, in 27° 33’ south, 47° 17’ east, on August 4th, Vaillant found the temperature 69:26° F.; and in 29° 34’ south, 46° 46’ east, the temperature of 67:84° F.; off South Africa, August 12, in 34° 42’ south, 27° 25’ east, the temperature 63:5° F.; on Au- gust 14, in 35° 41’ south, 22° 34’ east, a temperature of 63°3° F.; while off Cape Town, two hundred miles to the west, the temperature was 50° to 54° F.
In the above review, we have mentioned only a few of the obser- vations which have been used in laying down the lines, having selected those which bear directly on some positions of special interest, as regards geographical distribution.
The Chart also contains the heat-equator,—a line drawn through the positions of greatest heat over the oceans. It is a shifting line, varying with the seasons, and hence, there is some difficulty in fixing upon a course for it. We have followed mainly the Chart of Berg- haus. But we have found it necessary to give it a much more northern latitude in the western Pacific, and also a flexure in the western Atlantic, both due to the currents from the south that flow up the southern continents.
Vaillant, passing from Guayaquil to the Sandwich Islands, found the temperature, after passing the equator, slowly increase from 76° F., August 19, in 2° 39’ north, 91° 58’ west (of Greenwich), to 81-9° F., in August 31, 11° 15’ north, 107° 3’ west, after which it was not above 80° F.. The same place in the ocean which gave Vaillant 76° F., in August, afforded Fitzroy (4° north, 96° west), on March 26 (when the sun had long been far north), 822° F. This shows the variations of temperature that take place with the change of season.
REMARKS ON THE SEVERAL REGIONS. The form and varying breadth of the different regions, and the .
relations between the sea-temperatures of coasts in different latitudes, which they exhibit, are points demanding special remark.
1. Atlantic Torrid Region, between 74° F. north, and 74° F. south.— The form of this region is triangular, with the vertex of the triangle
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1469
to the east. Its least width is four degrees of latitude; its greatest width between the extreme latitudes, is forty-six and a half degrees, On the African coast it includes only a part of the coast of Guinea, and no portion is south of the equator. On the west, it embraces all the West India Islands and reefs (excepting the Little Bahama), and
the South American coast, from Yucatan to Bahia,—a fact that
accounts for the wide distribution of marine species on the American side of the ocean.
9. Atlantic Subtorrid Regions, between 74° and 68° F.—The North Subtorrid Region of the Atlantic is about six degrees in its average width, which is equivalent to a degree of Fahrenheit to each degree in surface. It encloses within the same temperature limits, a part of the east coast of Florida, between 24° and 274° north, and a part of the African coast, between the parallels of 9° and 143° north, the two related coasts differing ten degrees in latitude. ‘The Bermudas, in latitude 33°, and the Cape Verdes, in 152°, fall within this region.
The South Subtorrid Region has the same average width as the northern.
Taking the whole Atlantic Torrid or Coral-reef zone together, its width on the east is about twenty-one degrees, while on the west, it
“extends between the parallels of 30° south and 34° north, a breadth
of sixty-four degrees. As many species will thrive under the tem- perature of any part of the Torrid zone, the geographical range of such species in the Atlantic may be very large, even from Florida and the Bermudas on the north, to Rio Janeiro on the south, a range of which there are many actual examples.
Atlantic Warm Temperate Regions, between 68° and 62° F.—The northern of these regions has a breadth of fourteen and a half degrees along the west of Africa, and about seven degrees along the United States, south of Cape Hatteras, off the Carolinas, Georgia, and northern Florida. These shores and the Canaries are therefore in one and the same temperature zone.
The southern of these regions averages five degrees in width. The eastern limit on the African coast is sixteen to eighteen degrees to the north of the western on the South American coast.
Atlantic Temperate Regions, between 62° and 56° F.—The north Temperate Region is but a narrow strip of water on the west, termi- nating at Cape Hatteras, on the coast of the United States. To the
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1470 CRUSTACEA.
east it widens, and embraces the Azores and the African coast along Morocco, together with the Straits of Gibraltar, and a large part of the Mediterranean. Madeira lies upon its southern limit. It is, therefore, natural, that the same species should occur at the Azores, Madeira, and on the African coast, and be excluded wholly from the Atlantic coast of Europe. This, according to Prof. Forbes, is the fact with the Littorina striata, besides other species. The coasts of Portugal and the Azores are in different regions.
The South Temperate Region extends to Maldonado at the mouth of the La Plata, from near the parallel of 30°; along the African coast it reaches over more than twice the number of degrees of lati- tude, to within five degrees of Cape-Town.
Atlantic Subtemperate Regions, between 56° and 50° F.—The northern of these regions, like the preceding, can scarcely be distinguished on the coast of the United States, as the lines 50° and 56° F. fall nearly together at Cape Hatteras. On the eastern side of the Atlantic, it occupies the coast of Portugal to latitude 42° north, having a width of five degrees. It thus corresponds to the so-called Lusitanian Region.
The southern includes the mouth of the La Plata on one side, and on the other the coast near Cape Town, beyond which it extends to _ the Cape of Good Hope.
Atlantic Cold Temperate Regions, between 50° and 44° F.—The coast from Cape Cod to Cape Hatteras belongs to the Northern Cold ‘Tempe- rate Region. Passing easterly, this region is but a narrow line of water for thirty degrees of longitude, after which it expands, and finally terminates between Western Ireland and latitude 42° on the Spanish coast. The British Channel, the Bay of Biscay, and Vigo Bay, Spain, are within the limits of this region.
The southern embraces the coast of South America along by Rio Negro for about five degrees, and passes wholly to the south of Africa.
Atlantic Subfrigid Regions, between 44° and 30° F.—The coast of Massachusetts, north of Cape Cod, of Maine and Newfoundland, and all Northern Britain, the Orkneys, Shetlands, and Faroe Islands, per- tain to the Northern Subfrigid Region; while the southern, includes the Falklands, Southern Patagonia, and Fuegia.
Atlantic Frigid Regions, beyond 35° F.—Greenland, Iceland, and Norway are within the northern of these regions, and the South Shet- lands, Sandwich Land, and South Georgia, within the southern.
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. [471
Pacific Regions.-—A. comparison of the regions of the Atlantic and Pacific, and especially of the limits of those commencing at the South American coasts, brings out some singular facts.
The Torrid region of the Pacific, near the American coast, embraces only seventeen and a half or eighteen degrees of latitude, all but three of which are north of the equator; while that of the Atlantic covers a long range of coast, and reaches to 15° south. The south Subtorrid Region has a breadth of about three degrees on the Peruvian coast, reaching to 4° south, while that of the Atlantic extends to Rio Janciro, in 24° south. The Warm Temperate Region has a breadth of less than a degree, reaching to Cape Blanco, in 43° south, while that of the Atlantic extends to Rio Grande, in 33° south. The next or Temperate Region has a longer range on the South American coast, extending to Copiapo, in 272° south, and the Atlantic region corre- sponding goes to Maldonado in 35° south. The Cold Temperate Regions of the two oceans cover nearly the same latitudes.
On the North American coast at Cape Hatteras, the three isocrymes 62°, 56°, and 50° F., leave the coast together ; and in the Pacific on the South American coast there is a similar node in the system of isocrymes, the three 74°, 68°, and 62°, proceeding nearly together from the vicinity of Cape Blanco.
Viewing these regions through the two oceans, instead of along the coasts, other peculiarities no less remarkable are brought out. The average breadth of the South Torrid Region in the Pacific, is more than twice as great as that of the same in the Atlantic; and the most southern limit of the latter is five degrees short of the limit of the former in mid-ocean. So also, the Subtorrid Region at its greatest elongation southward in the Atlantic, hardly extends beyond the average course of the line of 68° F. in the Pacific, and the average breadth of the former is but two-thirds that of the latter. The same is true to an almost equal extent of the Warm Temperate and Tem- perate Regions.
The breadth of the Torrid Region of the Pacific to the eastward, where narrowest, is about six degrees; and to the westward, between its extreme limits, forty-nine degrees. The Torrid zone or Coral-reef Seas, in the same ocean, has a breadth near America, of about eigh- teen degrees, and near Australia and Asia, of sixty-six degrees.
New Zealand lies within the Subtemperate and Cold Temperate Regions, excepting its southern portion, which appears to pertain like
1472 CRUSTACEA,
Fuegia to the Subfrigid. Van Diemens Land, exclusive of its northern shores, is within the Cold Temperate.
Indian Ocean Regions —The Torrid Region covers the larger part of the Indian Ocean, including all north of the equator, and embraces the larger part of Madagascar. The Subtorrid extends just beyond Port Natal on the African coast (four degrees of latitude north of Cape Town), where there are coral-reefs. The Warm Temperate and Tem- perate regions each claim a part of the South African coast, arid the latter terminates at the Cape of Good Hope.
It hence follows that Port Natal, in latitude 30° south, the Hawaiian Islands, and Bermudas lie within regions of the same name. While Cape Town, in latitude 34° south, is in a like region with northern New Zealand, Valparaiso, the Atlantic shores of Portugal, and the sea between Cape Hatteras and Cape Cod.
Influence of Summer Heat.—The small annual range of temperature (twelve to fourteen degrees in most regions) has been remarked upon, and we have further observed, that the extreme heat has far less influ- ence on the distribution of species than the extreme cold. There are however some cases in the colder seas, in which the range has but half the extent here mentioned, and in such, the species are likely to differ from those characterizing the same region under other circumstances, approximating to those of the region next exterior. These cases are certain islands, or the extremities of continents, which are exposed to cold ocean winds and currents. ‘The south shores of Fuegia and New Zealand appear to be examples of this kind.
We add a table, enumerating the more important lands or coasts embraced in each of the regions, bringing together those which are of like temperature, and which consequently may be most closely related in species. It is partly in recapitulation of the preceding pages.
I. TORRID ZONE. 1. TORRID REGION.
A. ATLANTIC.—1. West India Islands.
2. Coast of South America, from the northeastern cape of Yucatan, to a degree south of Bahia.
3. Coast of Africa, from 9° north to 5° north.
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 473
4. Red Sea, to latitude 20° (?) north.
5. East coast of Africa, to latitude 264° (?) south. B. Inpran Ocean.—6. Coast of Persia, India, Malacca, Siam, and Cochin China, to
124° north, on the eastern coast of the last-mentioned country.
7. The islands of the Indian Ocean, north of 16° south, the northern two-thirds of Madagascar.
8. The East India Islands; also, the northern coast of Australia, from 22° south on the west side, to 25° south on the east side.
C. Pactric.—9. The Pacific Islands, between 20° north and 20° south, together with the Ladrones, New Caledonia, excepting the southern extremity, also the Tonga Islands, as far as Tongatabu, the Hervey Islands, the Paumotu Islands, as far as the Gambier Islands, and excluding Hawaii on the north.
10. The South American coast, from 174° north to 1° south.
2. SUBTORRID REGION.
A. Norra ATLANTIC.—1. The northern and western coast of Yucatan, and the coast of Mexico and Texas, within the Gulf of Mexico.
9. Key West, and the east coast of Florida to 27° north.
3. The Bermudas.
4. The coast of Africa, from 9° north to 144° north.
B. Sourn Atnanric.—5. The coast of South America, from below Bahia to a degree or two below Rio Janeiro.
6. Ascension Island and St. Helena.
7. West coast of Africa, from 5° north to 7° south.
CG. Inpran Ocean.—8. East coast of Africa, from 263° south to 31° south, including Port Natal; also, northern half of the Red Sea and the Persian Gulf.
9. South extremity of Madagascar, Isle of France, and Mauritius.
10. Western coast of Australia, between 22° south and 263° (?) south.
D. Norra Pactrrc Ocean.—11. Coast of Cochin China, between 124° north and 15° north.
12. Formosa, Loochoo (Liukiu), and neighbouring islands, southern shore of Japan, Hawaiian Islands.
13. West coast of North America, from the southern extremity of the peninsula of California to 174° north.
E. Sourm Pacrric.—14. A small part of the coast of Hastern Australia, between 25° south and 264° south.
15. The southern extremity of New Caledonia, Pylstaart’s Island, Mangaia, Rimetara, Rarotonga, Rurutu, Pitcairn’s, aster Island, and possibly the Gambier Islands.
16. The west coast of South America, near Guayaquil, from 1° to 4° south.
II. TEMPERATE ZONE.
1. WARM TEMPERATE REGION.
A. NortH Atuantic.—1. Coast of Gulf of Mexico, along Louisiana, Mississippi, 369
1474 CRUSTACEA.
Alabama, and the western side of Florida; also, the coast of the United States, from 27° north on the east side of Florida to Cape Hatteras.
2. The Canaries, and the coast of Africa, from 144° north to 28%° north.
B. Sourn ArTLantic.—3. East coast of South America, from a degree south of Rio Janeiro to 30° south; also, the west coast of Africa, between 7° south and 14° south.
C. Inpran Ocean.—4. South Africa, between 31° south in longitude 30°, and 33° south in longitude 23° east.
5. Western coast of Australia, between 264° south, and the southwestern cape, in latitude 34° south, including the vicinity of Swan River.
D. Norra Paciric OceaAn.—6. The Tonquin Gulf, Hainan Island, and the adjoining coast of China.
7. The western coast of the peninsula of California, as far as 283° north.
mani - © Soe ee eee! on eee ORI ss, site ree <.. ie asa al, teas BE EEA rn a 2 te oe - ———— nord Seite nag ence RRR RT iain -
2. TEMPERATE REGION.
A. Norta Ariantic.—l. Not distinguishable at Cape Hatteras.
2. Azores and Madeira, and the northwest coast of Africa, between the Straits of Gibraltar and 29° north.
3. The Mediterranean Sea, excepting probably the eastern coast and the southern coast east of Tunis, and including Algiers, Nice, Naples, and Sicily. The northern coast borders on the Subtemperate Region, or just passes into it.
B. Sours ArLantic.—4. The eastern coast of South America, from 30° south to the eastern cape of the La Plata, and not including Montevideo.
5. The western coast of Africa, between 14° south and 28° south.
©. Inpran Ocean.—6. Southern coast of Africa, between the Cape of Good Hope and the meridian of 23° east.
7. The southern shore of Australia.
8. The western part of Kiusiu, including the bay of Nagasaki. (Possibly Subtemperate. )
D. Norra Paciric Ocean.—9. Coast of California, between 284° north and 344° north, at Cape Conception, south of Monterey.
E. Sours Paciric.—10. Hast coast of Australia, between latitudes 264° south and 31° south(?).
11. West coast of South America, from Cape Blanco, north of Payta, in 44° south, to Copiapo, in 273° south.
3. SUBTEMPERATE REGION.
A. Norra Artantic.—1. Not distinguishable at Cape Hatteras.
2. Coast of Portugal, to 42° north.
3. Black Sea, excepting northern portion ?
B. Soura Atnantic.—4. Mouth of the La Plata.
5. West coast of Africa, from 28° south to Cape of Good Hope, including Table Bay.
C. Norrn Pactric Ocuan.—6. Southern part of eastern coast of Niphon, and the Yellow Sea, from south of Chusan.
7. Californian coast, from 344° north to Cape Mendocino,—including the Bays of Monterey and San Francisco. ,
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1475
D. Sourn Pactric.—8. Southeast angle of Australia, from 30° south, including Port Jackson. —
9. Northern island of New Zealand, nearly or quite to Cook’s Straits.
10. West coast of South America, from 273° south to 88°, including the harbours of
Coquimbo, Valparaiso, and Valdivia.
4, COLD TEMPERATE REGION.
A. Norra ATLANTrIc.—1. Coast of the United States, from Cape Hatteras to Cape Cod.
2. Southern Britain and Ireland, British Channel, Bay of Biscay, and northern coast of Spain to 42° north, including Vigo Bay(?).
B. Sourn Artantic.—3. East coast of South America, from the southern cape of the La Plata to 48° south, including the Bay of Rio Negro.
A. Island of Tristan d’ Acunha.
C. Inpran Ocran.—5. St. Paul’s and Amsterdam Island.
D. Pacrric.—6. Van Diemens Land, Middle Island of New Zealand, excepting southern extremity, Chatham Island.
7. Middle part of Eastern Niphon to 40° north.
8. West coast of America, from Cape Mendocino to Columbia River, or possibly to the Straits of De Fuca.
9, West coast of South America, from 38° south to 49° or 50° south, including Chiloe. :
5. SUBFRIGID REGION.
A. Norra ATLANTIC.—1. Massachusetts Bay, coast of Maine, Bay of St. Lawrence, and Southern Newfoundland.
2. Northern Britain, Orkneys, Shetlands.
3. Crimea and north coast of Black Sea?
B. Sourn Arnantic.—4. East coast of South America, below 43° south, including Fuegia and the Falklands.
CG. Inpran Ocran.—5. Prince Edward’s Island, Crozet, Kerguelen’s Land.
D. Pactric.—6. North part of Niphon, Yeso, the larger part of the Japan and Ok- hotsk seas; also the northwest coast of America, from 55° or 56° north, nearly or quite to the Columbia River.
7. South extremity of New Zealand, with the Aucklands, and other islands in the
vicinity.
Ill. FRIGID ZONE.
1. Eastern coast of North America, from the east cape of Newfoundland to the north. ward, with Greenland, Iceland, the coast of Norway, Cattegat. 2. South Shetlands, South Georgia, Sandwich Land, and other Antarctic Lands. The
line runs quite close to Cape Horn. 8 The Aleutian Islands, and- eastern and southern Kamschatka, and part of the
Kuriles.
Oe ee ae ap er a pre se
1476 CRUSTACEA.
The areas of the Torrid, Temperate, and Frigid zones of tempera- ture, either side of the equator, considering 27° as the normal limit between the first two of these zones, and 60° the limit between the Frigid and Temperate, are as follows :—
Torrid zone, ‘ .. 8,427,000 square miles (geographical) Temperate zone, ot 7,641,000 « & 6 Frigid zone, : . 2,486,300 « 6 6
It is hence seen that the Temperate zone, although six degrees wider than the Torrid, has not as large a surface. The species of marine life, if distributed equally over the two, would, therefore, be more numerous in the Torrid zone than in the Temperate, unless the — extent of ocean and coast line were far greater in the Temperate than in the Torrid zone, which is not the case. The ocean in the southern Temperate is much more extensive than that of the southern Torrid ; but the coast line is far less extensive in the former, as it does not abound in islands, like the Torrid zone.*
The range of temperature is far greater in the Temperate zone than in the Torrid, it being 20° F. in the latter, and 33° F. in the former.
In the Torrid zone, the Subtorrid Region has nearly one-third the
* The following table gives very closely the surface of the zones in square geographi- eal miles, for every 23 degrees of latitude to the parallel of 60°: it is taken from a larger table by Berghaus, in his Linder- und Volker-kunde, i.47. The first is the zone from the equator to the parallel of 23°, the second, from 24 degrees to 5 degrees, and 80 On.
24° . 809,824 SP _.sbackis EM 6 ag 808,200 35° 673,440 73° eS eee ae ee . 658,172 10°. 800,512 40° 631,656 123° a Paes Ca . 608,944 16° : 786,728 Ae. : 585,064 ee . 777,580 a . 560,320 20° : 766,952 50° : 534,032 ee ae . 506,960 740,544 5Bo 478,994 a . 726,408 ae . 441,792 30° 710,092 60°. 420,176
The zone from 60° to 70° has the area, . ; : 1,366,748 “ 70° to 30° : . 837,516 « sorte 90°, } 282,036
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1476
D. Sour Pactric.—8. Southeast angle of Australia, from 30° south, including Port
Jackson. 9, Northern island of New Zealand, nearly or quit 10. West coast of South America, from 273° south to 38°
Coquimbo, Valparaiso, and Valdivia.
e to Cook’s Straits. , including the harbours of
4, COLD TEMPERATE REGION.
tates, from Cape Hatteras to Cape Cod.
A. Norra Atiantic.—l. Coast of the United S el, Bay of Biscay, and northern coast
2. Southern Britain and Ireland, British Chann of Spain to 42° north, including Vigo Bay.(?)
B. Soura Arnanric.—3. Hast coast of South America, the La Plata to 43° south, including the Bay of Rio Negro.
4, Island of Tristan d’ Acunha. . C. Inpran Ocran.—5. St. Paul’s and Amsterdam Island. _D. Pactric.—6. Van Diemens ‘Land, Middle Island of New Zealand, excepting
southern extremity, Chatham Island. 7. Middle part of Eastern Niphon to 40° north. 8. West coast of America, from Cape Mendocino to Columbia River, or possibly to
the Straits of De Fuca. 9. West coast of South America, from 38° south to 49° or 50° south, including
Chiloe.
from the southern cape of
5. SUBFRIGID REGION.
A. Nort ATLANTIC.—1. Massachusetts Bay, coast of Maine, Bay of St. Lawrence,
and Southern Newfoundland.
2. Northern Britain, Orkneys, Shetlands.
8 Crimea and north coast of Black Sea?
B. Sourm Artantic.—4. Hast coast of South America, Fuegia and the Falklands.
CG. Inpran Ocran.—5. Prince Edward’s
D. Pacrero.—6. North part of Niphon, Yeso, hotsk seas ; also the northwest coast of America, from 55° or 56° to the Columbia River.
7. South extremity of New Zealand, w
vicinity.
below 43° south, including
Island, Crozet, Kerguelen’s Land. the larger part of the Japan and OK- north, nearly or quite
ith the Aucklands, and other islands in the
Ill. FRIGID ZONE.
1. Eastern coast of North America, from the east cape of Newfoundland to the north-
ward, with Greenland, Iceland, the coast of Norway, Cattegat. 2. South Shetlands, South Georgia, Sandwich Land, and other Antarctic Lands. The
line runs quite to Cape Horn. 3. The Aleutian Islands, and easter
Kuriles.
n and southern Kamschatka, and part of the
eS Ce ee a ee
ee ea
1476 | CRUSTACEA.
The areas of the Torrid, Temperate, and Frigid zones of ocean- temperature, either side of the equator, considering 27° as the normal limit between the first two of these zones, and 56° the limit between the Frigid and Temperate, are as follows :— oe
Torrid zone, d . 88,711,200 square miles (geographical). Temperate zone, ; 27,849,500 <“ &< “ Frigid zone, ! . Seo te: “ eee
It is hence seen that the Temperate zone, although two degrees ‘wider than the Torrid, has not as large a surface. The species of marine life, if distributed equally over the two, would, therefore, be one-fifth more numerous in the Torrid zone than in the Temperate, unless the extent of ocean and of coast line were far greater in the Temperate than in the Torrid zone, which is not the case. The ocean in the southern Temperate is much more extensive than that of the southern Torrid; but the coast line is far less extensive in the former, as it does not abound in islands, like the Torrid zone.*
The range of temperature is far greater in the Temperate zone than in the Torrid, it being 20° F. in the latter, and 33° FP. in the former.
In the Torrid zone, the Subtorrid Region has nearly one-third the
* The following table gives very closely the surface of the zones in square geographi- cal miles, for every 23 degrees of latitude to the parallel of 60°: it is deduced from a larger table by Berghaus, in his Linder- und Vélker-kunde, i. 47. The first is the zone from the equator to the parallel of 24°, the second, from 2% degrees to 5 degrees, and so on.
94° . 8,239,296 | 828° . 2,769,696 Genes soy -83232,;800 oy? =. 2,693,760 7H . 8,220,496 oy ae . 2,612,688 ae 8,202,048 se 2,526,624 124° LsBALTL AR 424° , 2,485,776 Bees, 3,146,912 45°... 2,340,256 174° . 8,110,820 474° . _ 2,241,280 a 8,067,808 ae 2,136,128 92,4° . 8,019,472 524° . 2,027,840 a5° ; 2,962,176 BBo 1,915,696 QT° . 2,905,632 57 H° ' . 1,767,168 20° ; 2,840,368 go°. 1,680,704
The zone from 60° to 70° has the area, . ‘ ‘ 5,466,992 He 100. tp BOS, = ; ‘ . 8,350,064 " oe aa pe : : 1,128,144
ste
ecient ne 8 enn =< =
ewern.e” = Nee ce comroeern
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. ]477
surface of the. Torrid Region, and not one-fourth as much coast line, | Tug facts which should be regarded in comparing the number of species of — |,
| (Se the two. | Ah ‘ . i i
Before leaving this subject of the Map, we add a few brief remarks, in a popular way, on the origin of the peculiar forms and positions : presented by the isothermal lines of the ocean. The great currents of 7 the globe are admitted to be the causes that produce the flexures and - modify the courses of these lines. These currents are usually of great ; depth, and consequently the deflecting land will be the deeply seated - glopes off a coast, beyond ordinary soundings. The eastern coasts of the continents either side of the equator, feel the influence of a warm equatorial current, which flows westward over each ocean, and is diverted north and south by the coasts against
which it impinges, and more or less according to the direction of the
coast. . The western coasts of the continents, on the contrary, receive a
strong polar current. In the southern oceans, it flows from the west- ward, or southward and westward, in latitudes 45° to 65° south, and is brought to the surface by the submarine lands or the submarine slopes of islands or continents; reaching the continents of Africa and South America, it follows along the western coast towards the equator. The same current, being divided by the southern cape of America, flows also, with less volume up the eastern coast, either inside of the warmer tropical current, or else on both sides of it. In the Northern Seas, the system of polar currents is mainly the same, though less regular; their influence is felt on both eastern and western coasts, but more strongly on the eastern. In the Atlantic, the latter reduces the tem- perature of the waters three or four degrees along the north coast of South America, as far nearly as Cape St. Roque. |
The cold currents are most apparent along the coasts of continents and about islands, because they are here brought to the surface, the submarine slopes lifting them upward, as they flow on. The limits of their influence towards the equator depends often on the bend of the coast; for a prominent cape or a bend in the outline will change the exposure of a coast from that favourable to the polar current to that favourable to the tropical, or the reverse. Thus it is at Cape Hatteras, on the coast of the United States; Cape Verde, on Western
Africa ; Cape Blanco, on western South America, etc. 370
Ter
Se 5a Tt — ae ger eer Se a a = et tn ES RATT NE he enn CIE: A OE AIEEE 5 IRN =. Fe Sano am hee 2 = : oe aoe - en . esa. 5A poral . a Eo ETON a corenamtenainae tt Wiese tae . ot ee ihe ee aR Pee eT ACR a3 ‘
1478 CRUSTACEA.
These are important principles modifying the courses of the oceanic isothermal lines ; we may now proceed to the application of them.
In the Atlantic, the warm tropical current flowing westward, is trended somewhat northward by the northern coast of South America, and still more so by the West India Islands, and thus it gradually curves around to parallelism with the coast of the United States. But south of Newfoundland, either wholly from the influence of the colder current which it meets with, or in part from meeting with submarine slopes that serve to deflect it, it passes eastward, and afterwards, where it is again free to expand, it spreads both eastward and north- eastward. The flexures in the isocrymes of 74° and 68° F., near the United States coast, thus have their origin. For the same reason, the line of 56° F. is nearly straight, till it reaches beyond the influence of the Newfoundland Banks, and then makes its Gulf Stream flexure, The line of 44° F. for the same reason,—the spreading of the Gulf Stream waters—diverges far from the equator in its easterly course, and even rises in a long loop between Great Britain and Iceland.
The cold currents, flowing down the eastern coast of America, bend the isocrymes far south close along the coast, and make a remarkable southern flexure in the isocrymes of 68° and 656° F. outside of the Gulf Stream flexure. So on the western coast of Britain, the isocryme of 44° F. has a deep southern flexure, for a like cause.
The waters of the tropical current gradually cool down in their progress, through the influence of the colder waters which they en- counter; and along the isocryme of 62°, they have in the colder seasons a common temperature with that of the ocean, so that the course of the Gulf Stream is but faintly marked in it. And also in the western half of the region covered by the isocryme of 56°, the colder and warmer waters have reached this as a mean temperature. Owing to the influence of the polar current on the northern coast of South America, the equator of heat lies at a distance from the land.
Up the western coast of Africa flows the cold current from the south and west, bending upward all the isocrymal lines; and passing north of the equator, it produces a large southern bend, off the coast of Africa, in the northern isocryme of 74° outside of the warm current flexure from the coast of Guinea, and also a large northern flexure in the heat-equator.*
* Along the ocean, near Africa, south and southeast of the Cape Verdes, Captain Wilkes found a current setting to the northward for much of the time until passing the equator.
tne i amenities a ne eee
- GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1479
| The Atlantic tropical current also flows in part down the eastern ij i coast of South America, giving a deep flexure to each of the isocrymes, ae besides making these lines to diverge from the equator, through all it their length. Again, the polar current passes northward nearer the 3 will coast-line, bending far back the western extremity of each of the :
isocrymes. In the Pacific, the tropical currents show their effects near the coast
of New Holland and China, in a gradual divergence of the lines from HEE
the equator. The ranges of islands forming the Tarawan, Radack, | i {|
oh and Ralick Groups, appear to divert the current northward in that | i
part of the North Pacific, and consequently the isocrymal lines bend | iN }
northward near longitudes 170° west and 180°; and near Niphon, AW that of 68° shows a still greater northern flexure.
The influence of the polar currents in this ocean is remarkably great. The southern flows from the west and south, bending upward : | | Hl the line of 56° F. along the South American coast, producing at Val- 1M paraiso at times a sea-temperature of 48° F. Still farther north, it bet throws the line of 68° F. even beyond the equator and the Galla- ay pagos; and that of 74° F., nearly one thousand five hundred miles ih from the coast, and four hundred north of the equator. The line of 62° F. reaches even beyond Payta, five degrees south of the equator, the sea-temperature at this place being sometimes below 61°.
The north polar current produces the same result along the eastern
coast of Asia, as on the eastern of America. The isocryme of 74° F, is bent southward from the parallel of 23° to 12° 30’ north; and that of 68° F. from 34° to 15° north, and the latter deflection is even longer
| than the corresponding one in the Atlantic. The trend of the coast opens it to the continued action of this current until the bend in the outline of Cochin China, below which the cold waters have less influence, although still showing some effect upon the heat-equator.
The isocryme of 44° is bent southward to Niphon, by the same cold
waters, and from this part of the northern Pacific the current appears to flow mostly between the islands of Japan and the continent.
In the Indian Ocean, the effects of the tropical current, as it flows westward, are apparent in the southern deflection of the several iso- crymes. The trend of the coast favours a continuation of the current directly along the coast, and consequently, its modifying influence on the sea-temperature reaches almost to Cape Town on the coast, and | passes even beyond it at sea, carrying 56° F. to the meridian of 15° -
east.
Se a
| | : | f | i ip hh ie es t ieee } i i Wie } ip j ie A wee a me itil | i} | - ih ime ih » ee | . ‘aa! { wt i t : } - } - i , 4 i | aé | i} a { i Bf - | : | ny 1 f | ei { -. : 5 { | I 7 ft 4 1 ig i Bia eat ; q \ 2a) | } ae mes | ; : ie ; ‘ee. : { I HF 4 A a 4 bi { i. ae nome ft |) ns 8 Pi i: Ee H 3 a ; - 1 § i i uh 328 ah ‘28 aT oH | va ie | cat ti ee ty « e | ‘| Fe | | * Bai i : y a) Be ia: ot t i 16 a 4 ie he 7 S
1480 CRUSTACEA.
%
By comparing the regions of the different oceans, north and south of the equator, we may arrive at the mean position of the several iso- crymes, and thereby discover on a grander scale, the influence of the various oceanic movements.
For the purpose of reaching mean results, the Middle Pacific 1s the most favourable ocean for study. This is apparent in its greater extent, and the wide distance between the modifying continents; and also no less in the greater actual regularity of the isocrymes.
We hence deduce, that the mean position of the isocryme of 74° F. is along the parallel of 20°, this being the average between the means for the North and South Pacific. In the same manner we infer that the mean position of the isocryme of 68° F. is along the parallel of 27°.
The southern isocrymes of 56° and 62° F., are evidently thrown into abnormal proximity by the cold waters of the south. This cur- rent flows eastward over the position of the isocryme of 44° F., and consequently in that latitude has nearly that temperature, although colder south. Hence, it produces little effect in deflecting the line of 44° F.; moreover, the line of 50° F. is not pushed upward byit. But the lines of 56° and 62° F. are thrown considerably to the north by its influence, and the Warm Temperate and ‘Temperate Regions are made very narrow. With these facts in view, we judge from a comparison of the North and South Pacific lines, that the mean position for the isocryme of 62° F. is the parallel of 32°; and for 56° F., the parallel of 37°; for the isocryme of 50° F., the mean position is nearly the parallel of 42°; for 44° F., the parallel of 47°; for 35° F., the parallel of 56°. There is thus a mean difference of five degrees of latitude for six degrees of Fahrenheit, excepting near the equator and between 35° and 44° F. These results may be tabulated as follows :*
Isocryme of 80° F.,_ . . ; . Parallel of 6° - 74°, . : ; ‘ tee: 20° 68°, : ; 27°
Gar) 9: d ; F ‘ 32°
56°, j ; ; ; } 37°
BO? . : , 42°
44°, ; ; : ; ; 47°
35°, . : : 56°
* We may hence deduce the temperatures of those isoerymes to which the parallels of latitude for every five degrees would normally correspond. They would be for 20°, 74° F.; for 25°, 70° F.; for 80°, 64-4° F.; for 35°, 58:4° F.; for 40°, 52-4° F.; for 45°, 46:4° F.; for 50°, 41° F.; for 55°, 36° F.; for 60°, 31° F.
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 148]
Using these results as a key for comparison we at once perceive the
great influence of the oceanic movements on climate and on the geo-
graphical distribution of marine life. The polar current of the Southern Atlantic has a more northward
course in mid-ocean than that of the Pacific. It consequently bears up the isocryme of 30° F. to the parallel of 50°, six degrees above the mean. The effect on the other isocrymes of the Atlantic is very remarkable. We perceive in the first place that the most southern point of each of these isocrymes is not far from the mean position of the same isocrymes in the Pacific, while the most northern point of each is ten to twenty-five degrees farther north. Taking the position of the isccrymes of 68° and 74° F., where they cross the meridian of 15° west, as the mean position for this ocean, we find that the former is eight degrees in latitude farther north than 68° F. in the South Pacific; and the mean for the latter is in 7° south, while for the same in the Pacific it is 20° south, making a difference of thirteen degrees. The effect of the cold southern waters is consequently not along the African coast alone, but pervades the whole ocean. It is hence obvious, how utterly untenable the common notion, that the tropical current from the Indian Ocean is the same which flows up the west African coast. With a temperature of 56° south of Cape Town, it would be wholly incapable of causing the great deflections for the whole South Atlantic which have been pointed out. It combines with the polar current, but does not constitute it. The facts thus sustain the opinions long since brought forward by the distinguished meteor- ologist Mr. Wm. C. Redfield, that the currents flowing north along the African and South American coasts are alike true polar or cold temperate currents.*
We may now turn to the N orth Atlantic. In this part of the ocean, the mean positions of the isocrymes of 74° and 68° F., are near the normal positions deduced from the Pacific. The line of 62° F. is in a somewhat higher latitude, the mean position, excluding the eastern and western deflections, being near the parallel of 36°. The line of 56° F. has the parallel of 422° north for its mean position over the middle of the ocean, which is five and a half degrees above the normal sn the Pacific. The line of 50° has in the same manner for its mean position over the mid-ocean, the parallel of 47%°, or again five and a
%* American Journal of Science, xlv. 299, 1843.
371
=
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——— aera TRA .
1482 CRUSTACEA.
half degrees above the normal position in the Pacific. The line of 44° ¥'. may be considered as having for its mean position the parallel of 52° north, while it rises to 60° north. The lines in the North Atlantic above that of 68°, average about five degrees higher in lati- tude than the mean normal positions, while 68° and 74° have nearly the same place as in the Pacific. There is hence a great contrast between the Pacific, South Atlantic, and North Atlantic Oceans. This is seen in the following table containing these results:
Normal, deduced Mean position in Mean position in from Pacific. South Atlantic. North Atlantic.
Isocryme of 74° F., 20° 7° south. 21° north. 68° 27° ci i 28° 62° 32° 29° 36° 56° 37° 36° 424° 50° 42° 39° - 473° 44° 47° 44°. 52° (max. 60° north). 35° 56° 50° 61° (max. —?)
The influence of the warm tropical waters in the North Atlantic lifts the isocrymes of 74° and 68° as they approach the coast of America, while the same lines are depressed on the east by the colder northern currents. Moreover, north of 68° the whole interior of the ocean is raised four to five degrees in temperature above the normal gerade, by the same waters spreading eastward; and between Great Britain and Iceland, the temperature is at least ten degrees warmer than in the corresponding latitude of the South Pacific, and thirteen or fourteen degrees warmer than in the same latitude in the South Atlantic.*
The influence of so warm an ocean on the temperature of Britain, and on its living productions, animal and vegetable, is apparent, when it is considered, that the winds take the temperature nearly of the waters they pass over. And the effects on the same region, that would result from deflecting the Gulf Stream in some other direction, as remarked by Prof. Hopkins} and others, and substituting in the Northern Atlantic the temperature of the Southern Atlantic, is also
* Ross, in his Antarctic Voyage, found the sea-temperature in 60° south and 3° west, 314° F., in the month of March; at the South Shetlands, 61° south, the sea-temperature was 31° to 35° in January (midsummer); and in the same latitude, and 45° west, it was 30°1° in February.
+ Quarterly Jour. Geol. Soc., vol. viii., p. 6, and Amer. Jour. Sci., 1853, vol. xv.
SOUTH AMERICA.
Pernambuco, 74°-88°. Bahia, 74°-83°.
Rio Janeiro, 684°—-78°. Buenos Ayres, 50°-642°. Rio Negro, 46°-60°. Fuegia, 36°-56°. Falklands, 37°-50°. Chiloe, 48°-562° Valdivia, 50°-638°. Conception, 52° ?-60°? Valparaiso, 52°-62°. Copiapo, 564° (July)-68° ? Iquique, 58° (J uly)-69° ? Callao, 574°-74°.
Payta, 60°-74° ? Guayaquil, 69°-81°. Gallapagos, 62°-80°.
NORTH AMERICA.
Panama, 74°-85°?
San Francisco, 51°-68°?
Monterey, 54°-70°?
Acapulco 82 4°-84° (March). + Columbia River, 46°-60°?
Puget’s Sound, 42° ?-57T°.
South of Newfoundland, 35°-63°.
Massachusetts Bay, 37°-64°. Cape Henry, 46°-80°.
Off Charleston, 64°-81°. Key West, 72°-89°. Yucatan, 71°-83°.
Cuba, 74°-84°.
temperatures of the waters, as of prominent importance in ma tremes in view are the means
consecutive days of the year.
Venezuela and Surinam, 74°-80°.
GEOGRAPHICAL DISTRIBUTION OF CRUSTACEA. 1483
obvious, without farther illustration. The discussion of these subjects
would be foreign to the topic b We close these general remarks, by giving the extreme surface nearly as ascertained, for some places.
rine zoological geography. The ex-
efore us.
of the coldest and warmest thirty
GREAT BRITAIN AND EUROPE.
Shetlands, 36°-56°?
Scotland, west and north, 89°-58°. Trish Sea, 45°-63°.
English Channel, 46°-62°.
Cape Finisterre, 50°-66°.
Near Gibraltar, 58°-77°.
Azores, 60°-738°.
Madeira, 62°-75°.
Canaries, 64°—-75°.
Cape Verdes, 70°-82°.
AFRICA.
Sierra Leone, 78°-85°. Ascension, 72°—78°.
St. Helena, 68°-74°.
Table Bay, 54°-68°.
Port Natal, 72°-73° (May).
INDIAN OCEAN.
South end of Madagascar, 69°-80°. Mauritius, 72°-83°.
Entrance of Red Sea, 76°-88°. Keeling Island, 78°-83° (April). Singapore, 74°-84°.
Balabac, 77°-85°.
Manilla, 79°-85°.
North Luzon, 74°-84°.
PACIFICO OCEAN.
Ladrones, 79°-86°. Salomon Islands, 77°-85°.
ST ICMR
1484 CRUSTACEA.
New Hebrides, 74°-83°. Hawaiian Islands, 68°-83°. New Caledonia, 73°-82°. Island of Hawaii, 72°-83°. Kingsmills, 80°-88°. Feejees, 74°-85°. NEW HOLLAND, ETC. Tongatabu, 74°-82°. Port Jackson, 55°-71°.
Samoan Islands, 74°-85°. Hobarton, Van Diemens Land, 50°-60°. Tahitian Islands, 74°-83°. Bay of Islands, N. Z., 54°-67°.
Hervey Islands, 68°-76°. King George’s Sound, 58°-68°.
A great service will be conferred on science when an isot