THE LIBRARY OF THE UNIVERSITY OF CALIFORNIA DAVIS A HISTORY BRITISH SESSILE-EYED CRUSTACEA BY C. SPENCE BATE, F.R.S., F.L.S., ETC., AND J. 0. WESTWOOD, M.A., F.L.S., HOPE PROFESSOR OP ZOOLOGY IN THE UNIVERSITY OP OXFORD, ETC. IN TWO -VOLUMES.— VOL. II. LONDON: JOHN VAN VOORST, PATERNOSTER ROW. M.DCCC.LXVIII. LIBRARY PRINTED BY WOODFALL AND KINDER, IVANE, STRAND, W.f!. BRITISH SESSILE-EYED CRUSTACEA. Order— AMPHIPODA. Group— NORMALIA. Division— HYPERINA. IN this DIVISION the eyes are generally developed to an abnormal size, often nearly occupying the whole surface of the head. The antennae are frequently absent, or, when present, more or less abnormal in their form, rarely ending in a multiarticulate flagellum. The ap- pendages of the mouth are rudimentary or obsolete. The arms are small and less powerful than the walk- ing legs, varying in different families from the simple to the complexly-chelate form. The body has the segments generally separate, although in some genera, as Phrosina, of which we have no British example recorded, the first two are fused together. The tail also has the segments usually distinct, but in some exotic genera, as Pronoe, Brachyscelus, &c., the fifth and sixth segments are incorporated into one. The appendages are more liable to aberration than in the Gammarida. The animals are remarkable for the paucity of hairs that exist upon their integumentary tissues, and are, for the most part, parasitic in their habits, attaching themselves to fishes or medusae ; they are able, however, to swim with ease. VOL. II. B » HYPERTNA. This division is synonymous with Milne Edwards's family of HYPERINES, and also with Dana's family of HYPERIDEA. It contains four families, two only of which have representatives in our British Fauna, namely, HYPERIID^E and PHRONIMID.E. Earn. I.— HYPERIID^E. The head is large and globular, being nearly occupied by the eyes. The superior antennae consist of a three- jointed peduncle and a flagellum, variable in length, but of which the first articulus is very long. The inferior antennae are formed of a peduncle and a variable flagel- lum. The first two pairs of legs are simple, but have the wrists more or less infero -anteriorly produced ; the other legs are generally subequal in size. The three anterior pairs of swimming legs resemble those of Gammarus, but the three posterior are broad, flat, and biramose ; the rami being lanceolate, and frequently serrated, but destitute of any ciliary fringe. The species are oceanic in their habits, and found to exist only in the gill cavities of the medusae. LESTRIGONUS. 3 A MPHIPODA . HYPERIIDjE. HYP ERIN A. Genus— LESTRIGONUS. (Edwards.} Lestrigonus. MILNE EDWARDS, Ann. des Sci. Nat. xx. p. 392. Hist, des Crust, iii. p. 81. DANA, U.S. Explor. Exped. p. 982. SPENCE BATE, Cat. Amph. Brit. Mus. p. 287. Generic character. Cephalon orbicular, deeper than broad. Segments of the pereion short, three times as deep as long. Pleon longer than the pereion ; first three segments long and the three posterior short. Eyes large, occupying the entire lateral walls of the cephalon. Antennae long, subequal, terminating in multiarticulate flagella. Mandibles having a triarticulate appendage. Gnathopoda complexly subchelate. Telson single, squamiform, triangular. THE head is large and rounded. The segments of the body are short, while those of the tail are much longer, the three anterior being the longest. The eyes are very large and occupy the whole of the lateral walls of the head, meeting nearly at the top and considerably en- croaching upon the facial surface. The antennae are of the same length, and are generally very long, never being shorter than the depth of the head and always terminating in a multiarticulate flagellum, the first articulus of which is very long, apparently consisting of several articuli fused together. The mandibles are furnished with a three-jointed appendage. The first two pairs of legs have the wrists infero-anteriorly pro- duced to a sharp angle ; the hand is narrow and the finger short and sharp, which, being capable of closing against the produced point of the wrist, forms with it a completely subchelate organ, very characteristic of the B 2 4 HYPERIIILE. whole of this division of Amphipod Crustacea. The walking legs are nearly of similar length, but have the coxae, especially of the two anterior pairs, not so deep as in the Gammarina, and the thighs less broadly de- veloped. The natatory appendages possess no con- spicuous distinction from other Amphipoda, but the three caudal pairs have the peduncles broad and flat, and the rami sharp and triangular. The middle piece is small, triangular, and squamiform. The geographical distribution of this genus appears to be world-wide, since it has been observed in the Atlantic as well as the Indian and Pacific Oceans, from the arctic to the tropical latitudes. LESTRIGONUS EXULANS. AMPHIPODA. HYPERIN4. LESTRIGONUS EXULANS. Specific character. Antennae reaching only to the third or fourth segment of the pereion ; inferior pair having the last joint of the peduncle termi- nating inferiorly in a small tooth or point. Propodos of each pair of gnatho- poda serrated. Lestriyonm exulans. KROYER, Gronl. Amfip. p. 68, pi. iv. f. 18, a, 6, c. EDWARDS, Hist, des Crust, t. iii. p. 82. SPENCE BATE, Cat. Amph. Brit. Mus. p. 287, pi. xlviii. fig. 2. THE head is oval, the vertical being the longer axis. The eyes are large, and occupy the entire lateral walls of the head. The antennae are nearly of equal length, and reach to about the third or fourth segment of the body. The superior pair are rather longer than the inferior, and have the first articulus of the flagellum longer than the 6 HYPERIIDj;. peduncle ; the remainder being very short, the basal ones being shorter than broad. The inferior pair have the last joint of the peduncle nearly as wide at the distal extre- mity as at the base, and terminating inferiorly in a strong tooth. The flagellum is suddenly narrower, and after the first articulus consists of several short articuli. The mandibles are broad and short, not terminating in teeth, or a sharp cutting blade. The molar denticle consists of a flat plate, furnished with a thick down of hair. The appendage has three joints ; the first extremely short, the others being equal, and the last terminating in a sharp point ; the whole being remarkably free from hairs. The first two pairs of legs are very small and sub-equal ; the first pair have the metacarpal joint and wrist inferiorly produced, and tipped with several stiff spines. The hand is narrow and tapering ; the inferior margin serrated, the serrature consisting of a series of rather long teeth, asso- ciated in groups of three, the longest in each group being the most anterior. The finger is slightly curved, and armed upon the inner margin with a serrature similar in character, but less regular in feature, to that of the pre- ceding joint. The second pair of legs much resemble the first, but have the wrist rather more infero-anteriorly produced. The hand is a little longer, and has the armature upon the inferior margin, as well as that of the finger, less distinctly marked. The other legs are nearly of equal length. The caudal appendages vary in length ; the penultimate pair being considerably the shortest, while the last are the broadest and longest, and have the inner ramus, as well as the inner margin of the outer ramus, freely serrated. The middle tail-piece is ovately lanceolate. The antennas in our British specimens are slightly longer than represented in Kroyer's figure of the type. LESTRIGONUS EXULANS. 7 We also observe that the peduncle of the second pair of antennae is not so decidedly truncate as in ours ; but, in spite of these differences, which are probably due to the delineator, we believe that our British form is identical with that of Kroyer's arctic specimen. The original specimen was taken by Kroyer in Green- land. British specimens have been sent to us from Carrickfergus, where they were found by Professor Kinahan, to whom we are indebted for the first British specimen ; from Cumbrae, where they were obtained by Mr. Robertson ; and they have been recently sent to us from Banff, where they were taken by Mr. Edward. The resemblance between this species and L. Gaudi- chaudii from Chili is very close, but the two species can be readily distinguished by the character of the armature on the hands of the first two pairs of legs. 8 HYPERinXE. A MPHIP ODA . HYPERIID^E. HYPERINA. LESTRIGONUS KINAHANI. Specific character. Antennae subequal ; the superior being rather the longer, equally the entire length of the animal. Length £ inch. Lestngonus Kinahani. SPENCE BATE, Cat. Amph. Brit. Mus. p. 289, pi. xlviii. fig. 4. THE resemblance between this species and Lestrigonus exulans is remarkably close ; so much so, that should the animals of either species lose their antennas, we believe that the most acute observation would not be able to detect any distinguishing feature. The antennae are rather longer than the animal, being nearly of equal length ; the upper are, however, some- what the longer. The peduncle of the superior pair is as long as the head, the first joint being longer than the two others. The first articulus of the flagellum is longer than the peduncle, tapering gradually to the extremity, and having the inferior margin fringed with hairs. The flagellum is very long and very slender, the articuli being about four or five times as long as broad, with the exception of a few succeeding the first long articulus. LESTRTGONUS KINAHANT. 9 The inferior pair have the peduncle reaching beyond that of the superior, and terminating abruptly, the flagellum being considerably narrower, and somewhat shorter, than that of the upper pair, although the articuli are similarly formed to those of the superior. In all other respects — except, perhaps, in the less unequal length of the caudal appendages — the description of L. exulans will suffice for this species also. The near resemblance of this species with that of L. Fabricii (M. Edw.) of the Indian Ocean and L. rubescens (Dana) of the Pacific, is quite as remarkable as that exist- ing between L. exulans and a species from Chili. The first specimen which we received was sent to us by Professor Kinahan, who captured it off Carrickfergus, and in compliment to whom we have named the species.* We have since received it in considerable numbers from Mr. Edward, of Banff. The colour, as far as we can judge from the dead ani- mals, is that of a salmon tint, with a few small spots of dull red. The eyes are probably green. * It is with much regret that we learn, while this sheet is passing through the press, that this able carcinologist has, at an early age, departed this life. 10 HYPERII1XE. A MP BIPOD A . H YPERIID^. HYP ERIN A. Genus— HYPERIA. (Latreille.) Hyperia. LATREILLE, in DESMAREST'S Consid. sur Crust, p. 258, 1825. MILNE EDWARDS, Ann. des Sci. Nat. xx. p. 387. Hist, des Crust, t. iii. p. 74. DANA, U. S. Explor. Exped. p. 986. SPENCE BATE, Cat. Amph. Brit. Mas. p. 292. Metoechus. KROYER, Gronl. Amfip. p. 60. MILNE EDWARDS, Hist, des Crust, iii. p. 78. Tauria. DANA, U. S. Explor. Exped. p. 988. Hiella. STRAUSS, Mem. du Museum t. xviii. Generic character. Cephalon large, orbicular. Eyes large, occupying most of the lateral, and encroaching upon the frontal, walls of the head. Antennse short, subequal. Gnathopoda nearly alike, small ; first pair nearly simple, the second complexly subchelate. Pereiopoda subequal. Three posterior pairs of pleopoda biramose. Telson squamiform. THE head is large and rounded. The body is broad and convex. The eyes occupy the greater portion of the lateral and dorsal walls, and encroach upon the frontal surface of the head. The antennae are short, being never longer than the depth of the head, and nearly equal in length. The lower pair are inserted at a consi- derable distance from the upper. The arms are small and imperfectly prehensile, but formed upon the com- plex type so generally prevailing in this division of Amphipoda. The walking legs are nearly of similar length, and tolerably strong. The caudal appendages are biramose, and the middle piece consists of a small lanceolate scale. Dana has, we think correctly, associated the genus METOECHUS of Kroyer with the present, from which it HYPER1A. 11 only differs in the infero-anterior angle of the carpus being more strongly developed. Mr. Spence Bate has also, in the Catalogue of Amphipoda of the British Museum, incorporated Dana's genus Tauria for a similar reason — namely, that the wrists are only de- veloped to a very small degree. In the same work Mr. S. Bate has also suggested that the species of the present genus are but the females of those of Lestrigonus. He arrived at this conclusion after examining a consider- able number of species of both genera, finding that it is difficult, if not impossible, to assert (with reference to the structure of the antennae) where one genus com- mences and the other ends. Recently, through the kindness of Mr. Edward, of Banff, we have had the opportunity of examining many fresh specimens both of Lestr ig onus and Hyperia, from the same locality, and we found that all the adult Hyperite of which the sex could be detected were females, but that none of the Lestrigoni were of that sex. 12 HYPERIIDyE. AMPHIPODA. HYPERIN4. HYPERIID^. HYPERIA GALBA. Specific character. Cephalon large ; pereion distended ; pleon compressed. Antennae short, having the flagella terminating in a few scarcely-visible articuli. First pair of gnathopoda having the carpus broad, but not obliquely produced; second pair having the carpus infero-anteriorly produced. Peduncle of the posterior pair of pleopoda reaching to the apex of the rami of the preceding pair. Telson lanceolate. Length \ inch. Hyperia Galba. MONTAGU, Linn. Trans, xi. p. 4, pi. 2, fig. 2. MILNE EDWARDS, Hist, des Crust, iii. p. 77. W. THOMPSON, Ann. Nat. Hist. xx. p. 244. WHITE, Cat. Crust. Brit. Mus. 1847 and 1850, p. 57. Hist. Brit. Crust, p. 206. GOSSE, Mar. Zool. p. 139. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Cat. Amph. Brit. Mus. p. 293, pi. xlviii. fig. 9. Hyperia Latreillii. MILNE EDWARDS, Ann. des Sci. Nat. xx. p. 388, pi. xi. fig. 1-7. Hist, des Crust, iii. p. 76. Regne An. (Ed. Crochard) Crust, pi. Iviii. fig. 1. HYPERIA GALBA. 13 GUERIN, Icon. R. An. Crust, pi. xxv. fig. 5. WHITE, Cat. Crust. Brit. Mus. 1847 and 1850. Hist. Brit. Crust, p. 206, pi. xi. fig. 3. GOSSE, Mar. Zool. p. 139, fig. 251. Metoechus medusarum. WHITE, Hist. Brit. Crust, p. 207. Hiella Orlignii. STRAUSS, Mem. du Museum, vol. xviii. pi. 4. THE head is large and rounded. The body is very con- siderably dilated, while the tail is much narrowed. The eyes are large and occupy nearly the whole surface of the head, distinguished by an exquisite soft tint of green when the animal is alive. The superior antennae consist of a short peduncle (the last two joints of which are shorter than the first) and a flagellum, which is not quite so long as the depth of the head ; this flagellum consists of a long articulus and a few faintly-marked terminal articuli, but these appear to be either not con- stant or only visible under treatment with liquor po- tassae. The inferior antennae are scarcely as long as the superior, and terminate in a flagellum nearly resembling that just described. The terminal articuli are, therefore, not to be depended upon as a specific character. The arms are small, and differ but slightly ; the second pair have the hand somewhat the longer, and the wrist some- what more infero-anteriorly developed than in the first pair ; both have the margin of the wrist fringed with strong but not very sharp spines. The walking legs are nearly of one length, and tolerably robust. The caudal appendages are broad and flat, and have the rami serrated at the margins. The peduncle of the last pair reaches quite to the extremity of the preceding, and the middle piece consists of a small lanceolate scale. The colour of the species, except the green eyes, is fawn, or faint yellow, passing into a salmon tint soon after the animal is put into spirits ; it is also dotted all over with small specks of red. 14 HYPERIID^E. We believe that Professor Milne Edwards was the first to point out the great difference of form existing between the young and the adult in this division of Amphipoda ; but Mr. Gosse, in his pleasant " Naturalist's Rambles in Devonshire," has figured the young of this species. We also have had an opportunity of examining them, a drawing from which is given at figure -u * at the head of this description. The head of the young animal is small, and the eyes, consequently, are not much deve- loped. The body is very large, while the tail is narrow and straight, and lies compressed beneath the body. Mr. Gosse has figured all the legs, but in our specimen two pairs appeared to be wanting. This may be accounted for by the circumstance that Mr. Gosse's specimens were older than ours, he having procured his as free and inde- pendent creatures, whereas ours were procured direct from the incubatory pouch. In the caudal appendages there also appears to be a difference in the degree of development as observed by Mr. Gosse and ourselves, arising, no doubt, from the above-named cause. This species, which must be considered as the type of the genus, was first taken by Col. Montagu on the southern coast of Devonshire, and it has been sent to us from Jersey by Mr. George Parker. Specimens from a Ehizostoma at Lamboy in Ireland have been communi- cated to us in Mr. W. Thompson's collection, belonging to the Belfast Museum, and a number of specimens stated to have been also captured in the stomach of a Medusa, and given to us by the late lamented Rev. Professor Henslow. Mr. White records it as inhabiting the pouches of Rhizostoma Cuvieri on the Dublin coast upon the autho- rity of Mr. Hyndman. Mr. Edward has sent it to us from * This mark is intended to symbolize the young animal. HYPERIA GALBA. 15 Banff, and Professor Milne Edwards mentions having found it on the shores of France. Among several specimens sent to us from Banff, were a few of a smaller size, which differed from the others in having much shorter antennae, the inferior being the shortest, and terminating in a more ohtuse extremity than in the larger specimens. We were at first inclined to describe them as a distinct species, but, all other condi- tions being considered, we feel certain that they are only immature specimens, a circumstance which induces us to think that probably H. medusarum (Fabr.) of the Arctic sea may likewise be but the young of this or some other species. The following vignette represents the little fishing vil- lage of Polperro, in Cornwall, a place that has been rendered attractive to naturalists as the scene of the la- bours, as well as the residence, of Jonathan Couch, Esq., F.L.S. 16 AMPHJPODA. BfPERINA. HYPERIT1XE. ffTPERIIDJB. HYPERIA OBLIVIA. Specific character. Superior antennae as long as the depth of the cephalon; Inferior antennae longer than the superior and terminating in a multiarticu- late flagellum. Grnathopoda subequal, carpi scarcely inferiorly produced. First and second pereiopoda having the carpi considerably broader than the propoda. Three posterior pairs of pereiopoda very long, subequal, and having the anterior margins fringed with fine comb-like cilia. Length 5^ inch. Hyperia oblivia. KROYER, Gronl. Amfip. p. 70, pi. iv. fig. 19. MILNE EDWARDS, Hist, des Crust, iii. p. 77. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Cat. Amph. Brit. Mus. p. 289, pi. xlix. fig. 5. WHITE, Pop. Hist. Brit. Crust, p. 206. THE head is deeper than long. The eyes are large, but the pigment in our dead specimen formed a black spot of distinct outline on the anterior edge of the HYPERU OBLIVTA. 17 lateral wall. The superior pair of antennae are about as long as the head is deep. The peduncle is short ; the flagellum stout at the base, gradually tapering to the apex, and is marked with a few imperfectly-defined rings. The inferior antennae are more slender than the superior, a little longer, and terminate in a multiarticulate flagellum. The hands can scarcely be described as sub- chelate, although they possess a tendency in the direction common to most animals in the division. The third and fourth pairs of legs are long, and have the wrists thicker than any other joint ; the hands are long and slender and tipped with sharp fingers. The three succeeding pairs are also uniform in shape, and nearly of equal length, the last being rather the shortest ; these have the sixth joint remarkably long, and have the anterior margin of each with the distal half fringed with short, straight, evenly-planted cilia, and a few scattered longer ones. The caudal appendages are rather long and slender. The colour of this species, if we can trust to that of an animal that has been dead a short time, appears of a light straw, having the back starred with a few spots of black pigment. We have frequently doubted whether this species strictly belonged to the present genus. But finding that it agreed very closely with H. trigona, of Dana, from Cape Horn, we have considered it desirable that it should remain therein for the present. The form of the first two pairs of walking legs differ from the more typical species. The two succeeding pairs of legs in their length and armature suggest a relationship to the genus Cyllopus, which is also supported by the form of the inferior pair of antennae, but from that genus this VOL. II. C 18 HYPERIIDJ:. species is excluded by the length of the last pair of walking legs, which in Cyllopus are rudimentary. This species was first taken by Kroyer, in Greenland, from whence it is also recorded by Milne Edwards. The specimen from which our description and figure are taken was sent to us from the Moray Frith by the Rev. Geo. Gordon, to whom we are indebted for the accom- panying sketch, taken by Miss Gordon from a scene on that Frith. DOUBTFUL SPECIES. 19 DOUBTFUL SPECIES. THE Gammarus nolens, Johnston (Zool. Journ. iii. p. 179) has been referred to the present family, as a species of the genus Typhis of Risso, without sufficient founda- tion,* and probably in consequence of its supposed rela- tionship to Montagua monoculoides, which was mistaken by White and Gosse for a Typhis. Vide page 54. It is de- scribed as about three or four lines long, and not much compressed. The antennae are not more than one- third the length of the body, the superior pair being the shortest ; the first and second pairs of legs monodactyle ; the first with a small hand, the second with the hand more dilated ; the legs monodactyle and spinous ; the two pairs of caudal processes having mucronate branches, and the middle tail-piece is simple, terminating in a papilla, without any terminal processes. It is described as not being rare near Berwick-upon- Tweed, and as inhabiting confervas, but we have not seen a specimen. * Typhis nolens. WHITE, Cat. Crust. Brit. Mus. p. 78. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Rep. Brit. Assoc. 1860, p. 225. Anmyx (?) nolens. WHITE, Pop. Hist. Brit. Crust, p. 169. c 2 20 PHRONIM1D.E. Fam. II.— PHRONIMID.E. INFERIOR antennae obsolete, in one sex at least. Organs of the mouth rudimentary. Third pair of pereiopoda developed more or less perfectly into a prehensile organ. This family corresponds with that of Dana, except that it does not include the genus Phorcus. It is divided into two sub-families, the PHRONIMIDES and PHROSI- NIDES, the former only of which has, as yet, been included in the Fauna of Great Britain. Subfamily— PHRONIMIDES. THREE posterior pairs of caudal appendages, biramose rami lanceolate. This subfamily corresponds with Dana's division PHRONIMIN.E, exclusive of the genus Primno. PHRONIMA. 21 A MPHIPODA . PHRONIMIDES. HYP ERIN A. Genus— PHRONIMA. Pkronima. LATREILLE, Hist. Nat. Crust, et Ins. vi, p. 289. SPENCE BATE, Cat. Amph. Brit. Mus. p. 316. Phronyma. LEACH, in Sam. Ent. Comp. p. 101. Phronoma. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Generic character. Cephalon large, broadest at the .top, and gradually decreasing to the oral aperture. Eyes upon the dorsal surface of the cephalon. Superior antennae imperfectly developed. Inferior autenna3 obsolete. Mandibles without an appendage. Pereion broad and flat. Guathopoda small ; carpi having the infero-anterior angles produced. Pereiopoda, con- sisting of but six joints, third pair chelate. Pleon narrow. Three posterior pairs of pleopoda biramose, lanceolate. Telson small, single. THE head in this genus is much broader at the top than at the mouth. The body is tolerably broad, and the tail is very narrow. The eyes are large, and placed upon the top of the head. The superior antennae are but imperfectly developed, consisting only of two joints, one probably representing the peduncle, the other the flagellum, the latter armed along two-thirds of its distal length with about sixteen long flattened filaments. The inferior antennae appear to be altogether wanting. The mandibles are without an appendage. The first two pairs of legs are small, and have the wrists inferiorly produced, and each terminates in a minute finger, flanked at the base on each side by a small wing-like process, which Mr. Spence Bate, in the Catalogue of the British Museum, has named dactyloptera. The remaining legs only possess 22 PHRONIMID^E. six joints in each, but which of the joints is missing is difficult to determine. Observing, however, that the finger in the first two pairs is reduced to a rudimentary condition, and knowing the tendency in this division for the wrist to assist in forming the prehensile condition of the organ, we presume that the last joint is either wanting or fused with the preceding. In one instance we have ob- served a minute dactylos at the extremity of the second pair of pereiopoda, but so minute that it was not ap- preciable to less than 60 diameter magnifying power, and it is most probable that it is absent from being generally worn away. (We have a parallel instance in the allied subfamily Phrosinides. In the genus Phrosina the num- ber of joints is six, whereas in Primno it is seven. Five joints of the legs resemble each other in the two genera, but in Primno the finger is added to the extremity.) The fourth pair of legs are very perfectly chelate. The caudal appendages are biramose, the rami being short and spear-shaped. The middle tail-piece is small, and slightly emarginate at its extremity. The animals of this genus are generally to be met with in tropical and subtropical waters and the Mediterranean. The few specimens which we know to have been met with in the Temperate Zone, have been probably borne thither by various oceanic currents. PHRONIMA SEDENTARIA. A MPHIPODA . HYPERINA. PHRON1MIDES. PHRONIMASEDENTARIA. Specific character. Cheliform organ on the third pair of pereiopoda slender. The inner margins of each ramus of the chela furnished with one tubercle, both tubercles finely tuberculated. Length 1 inch. Cancer sedentarius. FORSKAAL, Descript. Anim. Arab. p. 95. Cancer (Oammarellus) sedentarius. HERBST. Naturg. der Krabben, &c. , ii. pi. xxxvi. fig. 8. Phronima sedentaria. LATREILLB, Gen. Crust, et Ins. i. p. 56. pi. ii. fig. 2. Hist. Nat. des Crust. et Ins. vi. p. 289, pi. Ivi. LAMARCK, Hist, des Anim. sans Vert. v. p. 197. LEACH, Trans. Linn. Soc. xi. p. 355. SAMOUELLE, Ent.Comp. p. 101. DES- MAREST, Cons, sur Crust, p. 257, pi. xlv. fig. 1 (after Risso). MILNE EDWARDS, Ann. des Sci. Nat. xx. p. 394 ; 2 ser. iii. pi. xiv. fig. 9. Hist, des Crust, iii. p. 93, pi. x. fig. 13. CUVIER, Regne Anim. 2nd edit. v. (edit. Croch.) pi. Iviii. fig. 3. 24 PHRONIMID.E. GUEKIN M^N., Icon. R. An. Crust. pi. xxv. fig. 4. LUCAS, Expl. dans Algerie, t. v. fig. 5. WHITE, Cat. Mus. Brit. Mus. 1847, p. 50. Pop. Hist. Brit. Crust, p. 208, pi. xi. fig. 4. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 152. Cat. Amph Brit. Mus. p. 316, pi. L. fig. 1. THE head is deeper than long, tapering gradually towards the mouth. The antennae are short, arid almost rudimentary, having but two joints, the basal one short, the second about four times as long, furnished with several membranous cilia along its distal portion. The upper lip is a broad, thin plate, with a deep and narrow notch in the middle. The mandibles consist of large and squami- form plates, having the cutting margin formed into a smooth hoe-like blade. The right blade is furnished with a small second articulate plate, and both have the molar process developed in the form of a flat plate, perpendicular to the cutting margin, and fringed with short cilia. The first pair of foot-jaws consist of a basal joint and two branches, the one being somewhat lance-shaped and flat, having the outer margin smooth, but the inner serrated ; the teeth being curved anteriorly and slightly overlapping each other. The second branch is hollow, or cup-shaped, having the margin evenly pectinated. The second pair of foot-jaws also consist of a basal joint and two ciliated oval plates, pointed at the tips. The under lip also consists of a basal joint, rather longer than wide, termi- nated by two lateral pointed lobes, having a double row of serratures on the inner margin, and furnished with a third central acute inner lobe. The first two pairs of legs are very similar, having the infero-anterior margin of the wrist anteriorly serrated ; and in the first it is a little more produced anteriorly than in the second. The hand is long, slender, cylindrical, and tapering. The finger is PHRON1MA SEDENTARIA. 25 short, terminating in a minute double point, and flanked on each side at the base with two little wing-like appendages. These are smooth and arcuated upon the upper margin, but straight and regularly pectinated along the lower. The next two pairs of legs are long and simple ; the succeeding pair are developed into the form of a perfect claw, each branch having a tubercle near the base on the inner edge, these tubercles being finely tuberculated ; the last two pairs of legs are short and simple. The natatory appendages are short, but have a robust peduncle. The caudal appendages resemble each other, but the penultimate pair are about half the length of the others. They consist of a long, slender peduncle and a couple of styliform branches. The middle tail-piece is very small. Dr. Pagenstecher, of Heidelberg, has published a very interesting anatomical and physiological memoir on this species in Wiegmann's " Archiv fiir Naturgeschichte," for 1861, in which he has made us acquainted with the early and intermediate states of the animal. In the earliest condition the antennae are very small, dilated, and jointlessj the seven pairs of legs are of uniform size and shape, each consisting of seven joints, including the small basal joint by which it is attached to the body, and the very minute terminal hook. The joints of the tail are almost undeveloped, the whole tail being scarcely larger than the preceding segment. In the intermediate state the third and fourth pairs of legs are considerably elongated, and the fifth pair have become cheliferous.* The tail and its appendages have also acquired consi- * The progress of development in this genus offers a curious contrast to that of Bmchyscclus crusculum as described by Spence Bate, "Annals of Natural History " for July, 1861, in which the sixth pair of legs are cheliferous in the young stage, becoming simple in the adult. 26 PHRONIMID^E. derable development, although still shorter and compara- tively more robust than in the perfect animal. The eyes, in the perfect state, have afforded very interesting details. In addition to the lateral pair of the ordinary form, connected with the lateral extremities of the brain, are a superior pair of organs of sight, the nerves of which are considerably elongated, arising from intermediate dila- tations of the brain, and terminating in a mass of small knobs. The basal portion of these nerve-filaments forms a dark red mass, so that, in these respects, the animal is quite analogous toAmpelisca Gai?nardii, described in our Vol. i. p. 128. The only specimen of this species which we have seen as a native of the British coast, is one in the British Museum, taken by Dr. Fleming on the 3rd November, 1809, at Burray, in Zetland, amongst rejectamenta of the sea. This specimen, unfortunately, is in a very dilapi- dated condition. We have, therefore, found it necessary to present our readers with a figure drawn from a speci- men of unknown habitat, with which we have compared the British type. Other specimens from the Shetland Islands were obtained by the late Dr. Johnston, and exhibited by him before the Berwickshire Naturalists' Club in 1855 (Proceedings, iii. p. 212). The animal is more abundant in warmer latitudes; and the fact of its having been found so far north is to be attributed, probably, to the currents of the Great Gulf Stream. Risso describes the animal as being transparent, shining, and covered with red spots. Desmarest says that it is to be found mostly in the cavities of Pyro- soma and Beroe. Several specimens of the Phronima within the latter animals, open at both ends, are pre- served in the Hopeian Collection at Oxford ; the cavity of the latter, in one instance, containing a large num- PHRONIMA SEDENTARIA. 27 her of young PhronimcB^ in company with their parent. In the British Museum is a specimen of Doliolum papil- losum, of Delle Chiaje, from Naples, in which a specimen was found, and which is represented in our figures at the head of this description,* the small white dots repre- senting small masses of calcareous matter. Mr. Mac- Donald has informed us that he has kept some alive while inhabiting specimens of Doliolum, and that it was chiefly through the agency of the crustacean that the medusa was propelled through the water, adding that as they progressed they frequently rolled over and over. * Figured also by Delle Chiaje, " Animali Invertebrati, tav. xxiii. ; see also Otto, in " Nova Acta," xi. p. 313. 28 ABERRANTIA. Group— ABEEBANTIA. THIS group is distinguished from the more typical Amphipoda by the abnormal condition or the absence of one or more segments of the pleon, as well as by the coxae not being largely developed into scales, and being mostly fused with their respective segments of the pereion. This group comprises the genus Dulichia together with the L^MODIPDA, an order founded by Latreille to sepa- rate the genus Caprella from the ISOPODA, amongst which naturalists had previously arranged it. It corresponds with the order L^MODIPODA of Milne Edwards, including the family Dulichiida of Dana. Fam. I.— DULICHIID.E. PEREION six-jointed ; the last two segments fused into one. The last segment of the pleon absent. Telson squa- miform. Fifth pair of pereiopoda attached to the pos- tero-inferior angle of the sixth segment. Posterior pair of pleopoda wanting. In the typical forms of Aberrant Amphipoda, all the legs have the coxae fused with the respective segments of the body, and the tail is reduced to a rudimentary condi- tion. In CERCOPS the tail, though rudimentary in appearance, has, according to Kroyer's figure, but one segment wanting. The absence of the natatory appen- dages, as well as of the first two pairs of walking legs, approximates this genus to Caprella. It is clear, there- DTJLTCHIID^;. 29 fore, that the only persistent character distinguishing the ABERRANTIA from the NORM ALIA is the absence of one or more segments from the tail. We are justified, conse- quently, in associating this family with the Aberrant rather than with the Normal group of Amphipoda, amongst which it has been previously arranged. As yet, but a single genus is known belonging to this family. The Vignette below represents a sketch taken by Dr. Walker of a jetty at New Brighton on the Mersey, off the mouth of which he took some animals of this genus. 30 ABERRANTIA. A MPHIP ODA . D ULICHIID^E. Genus— DULICHIA (Kroyer). Dulichia. KROYER, Nat. Tidsk. n.s. i. p. 521. Voy. en Scand. pi. xxiii. fig. 1. SPENCE BATE, Ann. Nat. Hist. xx. p. 526. Dyopedos. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Generic character. Superior antennas longer than the in- ferior. Inferior antennas inserted posteriorly to the superior. Gnathopoda chelate. Pereiopoda subequal, having neither the coxae nor basa developed into scales. Three anterior pairs of pleopoda normal ; fourth and fifth terminating in two styliform rami ; sixth obsolete. Telson single, lanceolate. IN this genus the animals have the bodies long and narrow; the eyes normal; the superior antennae longer than the inferior, both pairs carrying short flagella. The inferior pair arise farther back than the superior. The hands of the first two pairs of legs are more or less chelate. All the legs have the first joint small and squa- miform, that of the last two pairs being fused with the fifth segment of the body. Each of the caudal appen- dages terminates in two styliform rami. The middle tail- piece is single and pointed. This genus appears to be essentially arctic. It was from thence that Kroyer obtained the type of the genus, specimens of which we have seen attain the length of one inch and a quarter. The species taken on the northern shores of this island scarcely reach to the length of a quarter of an inch, while those from the western shores are still smaller. DULICHIA PORRECTA. AMP HIP OD A. ABERRANTIA. 31 DUL1CHIIDM. DULICHIA PORRECTA. Specific character. Cephalon not produced into a rostrum. Pereion and pleon dorsally smooth. Eyes round, not elevated upon a tubercle. Superior antennae about half the length of the animal ; flagellum shorter than the last joint of the peduncle. Second pair of gnathopoda having the propodos long and armed with two straight and anteriorly- directed teeth, the posterior one being the longer. Length | inch. Dulichia porrecta. SPENCE BATE, Cat. Amph. Brit. Mus. p. 348, pi. liv. fig. 9. Ann. Nat. Hist. xx. p. 526. WHITE, Pop. Hist. Brit. Crust, p. 209. Dyopedos porrecta. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. THIS species differs from D. spinosissima, on which Kroyer founded the genus, in the following particulars : — The head is not produced forwards into a sharp rostrum ; the body and tail are smooth, being free from teeth or spines. The eyes are round, but not raised upon a stout tubercle. The superior antennae are about half the length of the extended animal. The first joint of the peduncle is short and robust, but the two succeeding are long and slender. The flagellum (probably) is about half the length of the last joint of the peduncle. 32 DULICHinXE. The inferior antennas are shorter than the superior, reaching scarcely to the extremity of the peduncle of the superior. The first pair of legs have the hand small, short, and oval, the pajm being oblique and imperfectly defined. The second pair of legs are much larger than the first, and have the hand long, but not very broad. It is armed anteriorly and inferiorly with two long, straight teeth, directed forwards, the posterior being the longer. The finger is short, thick, and double-lobed upon the inner margin. The coxae of the second pair of legs are produced in front to a point. The caudal appendages are sub-equal, and the middle tail-piece is pointed. We first received this specimen from Mr. Gregor, of Macduff, who procured it from the Moray Frith, and subsequently from Dr. Walker, who took it in deep water between the rivers Dee and Mersey. The specimens received from Dr. Walker differ from the type of the species so much that we hesitated in con- sidering them identical. After full consideration, how- ever, we feel assured that the alteration of form is one of variation, dependent upon some altered conditions in the history of the animal. The specimens from the mouth of the Dee have the hand of the second pair of legs shorter, stouter, and more oval than in the type, but the armature is the same, except that the inferior tooth is not quite so far behind the first, and not directed so straight forwards. One of these specimens was a female, and, fortunately, the larva were in a mature condition, which enabled us to ascertain that the absorption of the seventh into the sixth segment is a feature from the earliest existence of the animal. The larva is distinguishable from the adult by the shortness of the antennae, the small sizes of the hands, and the shortness of the last pair of legs. DULICHIA FALCATA. AMPHIPODA. ABERRANTIA. 33 DULICHIIDjE. DULICHIA FALCATA. Specific character. Cephalon without a rostrum. Body smooth. Superior antennae about two-thirds the length of the animal. Second pair of gnatho- pocla having the propodos armed beneath with a crooked tooth near the base, and a sharp curved tooth near the distal extremity. Length, | inch. Dulichia falcata. SPENCB BATE, Ann. Nat. Hist. xx. p. 526. Cat. Amph. Brit. Mus. p. 348, pi. liv. fig. 10. WHITE, Pop. Hist. Brit. Crust, p. 209. Dyopedos falcata. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. IN general appearance this species closely resembles the preceding. The head is not produced into a rostrum. The body and tail are smooth, being free from teeth or spines. The eyes are round, and rather large. The superior antennae are long, quite two-thirds the length of the animal. The first joint of the peduncle is shorter than the head, but each of the two succeeding (which are slender, and nearly of the same length) are three times as long as the first. The flagellum is not so long as the last VOL. II. D 3* DULICHIDXE. joint of the peduncle. In our unique specimen, which is also imperfect in other parts, the inferior antennae are lost. The first pair of legs have the hand tapering to the distal extremity. The palm is very oblique, and but very imperfectly, if at all, defined. The second pair of legs are very robust, and have the hand long, the palm armed with two curved teeth, the distal tooth being sharp and slightly curved, the basal (by which the limit of the palm is defined) being crooked. The finger is rather long, sharp, curved, and slightly waved upon the inner margin. The third and fourth pairs of legs are smaller than the three succeeding, which are very long, and furnished with fine hairs upon the under surface of the fifth joint. We also received this species from Mr. Gregor, of Macduff. It came to us mixed with D. porrecta and some imperfect specimens which had no teeth on the hand. These latter we believe to be females of this species. It was taken in the Moray Frith. CAPRELLID^. 35 Fam. II.— CAPRELLID.E. PEREION cylindrical. Pleon rudimentary. Appendages attached to the cephalon normal and well-developed. Pereiopoda having the first joints, or coxse, fused with the segments of the pereion to which they are respectively attached. Branchiae attached to the third and fourth segments of the pereion. Pleopoda rudimentary or obsolete. It is to the species belonging to the several genera in this aberrant family that the popular name of spectre or skeleton shrimp has been applied, the idea being sug- gested by their thin and skeleton appearance, as they crawl among the weeds under water. The slender elongated form of these animals well con- trasts with the short and dilated bodies of those com- posing the following family Cyamidae. These animals also are free and roving in their habits, whilst the Cyami are parasitic upon the Cetacea, and evidently, from their structure, sluggish in their movements. The Caprellidae have recently been divided by Kroyer into several genera beyond those adopted in the following pages, founded, for the most part, on the relative structure of the minute terminal portion of the body, and the greater or less development of its rudimental segments and appendages. These characters appear, however, to us of too slight importance to warrant such a step, the more so since they only exist in an abnormal condition. D 2 36 CAPRELLTD.E. A MPHIP 01) A . CA PRELUDE. ABERRANTIA. Genus— PHOTO. Proto. LEACH, Linn. Trans, xi. p. 362, 1814. DESMAREST, Consid. sur Crust, p. 276, 1825. SPENCE BATE, Cat. Amph. Brit. Mas. p. 349. Leptomera. LATREILLE, in CUVIER, Regne Animal, 1st ed. iii. p. 51, 1817. DESMAREST, Consid. sur Crust, p. 275. GTUERIN, Icono- graph, R. An. Crust, pi. xxviii. fig. 3. KROYER, Nat. Tidsk. iv. p. 496. MILNE EDAVARDS, Hist, cles Crust, iii. p. 109. GOSSE, Mar. Zool. i. p. 131. Naupredia. LATREILLE, in CUVIER, Regne Animal, 2nd ed. iv. p. 128. Cours d'Entomol. p. 393. VAN BENEDEN, Faune litt. de Belgique. Generic character. Cephalon confluent with the first seg- ment of the pereion. Pereion having the last joint shorter than the preceding, cylindrical. Pleon rudimentary. Gnatho- poda subchelate. Three anterior pairs of pereiopoda short and feeble, last two long and powerful. IN this genus the head is small and globular, and so closely attached to the first segment of the body that it can only be distinguished from it by close observation. The body is cylindrical, and the tail is rudimentary. The eyes, antennae, and organs forming the mouth are similar to those in the group NORMALIA, but the legs have the first joint closely fused with the respective segments to which they are attached. In this respect we perceive a resemblance to the development of the same parts in the highest organized decapods. Many genera of the Bra- chyura have the coxae as closely anchylosed with the pereion as we here see exhibited in animals at the oppo- site extremity in the scale of development. The first two pairs of legs are subchelate, the second being the larger. The next four pairs are equidistant from each PROTO. 37 other, while the seventh pair are much nearer the sixth. The fifth pair of legs are the shortest, the fourth pair being longer, and the third still a little longer. The last two pairs of legs are long and powerful. The branchiae are attached to the second, third, and fourth pairs of legs. The tail is rudimentary, and the appendages at- tached to it almost obsolete. The geographical range of this genus is, as yet, limited to the British seas and the adjacent coast, with the exception of a single specimen taken by Dana on the south-eastern shores of South America. Latreille appears to have made much confusion respect- ing the nomenclature of the present group by attempting, in his different works,* to distinguish his genus Leptomera from that of Proto of Leach, proposing also a third generic name Naupredia (Naupridia, Milne Edwards), for an animal described as having only ten legs in a con- tinuous series, those of the second, third, and fourth pairs having a vesicle at the base, and which is evidently a Proto with the sixth and seventh pairs of legs acci- dentally broken off.f He has evidently, also, fallen into error in giving the Gammarus pedatus of Montagu and of Miiiler and the Squilla ventricosa of Miiller as three distinct species, referable to separate sections or sub- genera. * Regne Animal, 1st edit. iii. p. 51 ; 2nd edit. iv. pp. 127, 128. Nouv. Diet. d'Hist. Nat. 2nd edit. p. 433 (Art. Chevrolle) ; xvii. p. 485 (Art. Leptomere) ; xxviii. p. 177 (Art. Proton). f Van Beneden (Recherches sur la Faune litt. de Belgique, Crust. 1861, p. 97, pi. xvii.) has described a species which he names Naupredia tristis, asserting that it is a perfect animal, and not a mutilated Proto (Leptomera). It is only five millemetres long, and is most probably in a very young state. It entirely agrees with Proto, except in the inarticulated flagellum of the antennae and want of the four hind legs. It is possible that these may be subsequently developed ? 38 CAPRELLID/E. AMPH1PODA. ABERRA.NT1A. CAPRELLID^E. PHOTO FED AT A. Specific character. Superior antennae nearly half the length of the animal. Inferior antennae about half the length of the superior. First pair of gnathopoda having the propodos triangular, palm oblique, armed with small spines, and denned by a sharp tooth. Second pair of gnathopoda having the propodos long, ovate ; palm waved, being oblique nearly two- thirds the length of the joint, and defined by a process, armed with a strong spine. Length £ inch. Gammarus pedatus. Cancer (Gamm-arus) pedatus. Proto pedata. ABILDGAARD in MULLER, Zool. Dan pt. iii. p. 33, pi. ci. figs. 1, 2. MONTAGU, Trans. Linn. Soc. xi. p. 6, pi. ii. fig. 6. FLEMING in Edin. Phil. Journ. viii. p. 296. LEACH, in Edin. Encyc. vii. p. 433. Trans. Linn. Soc. xi. p. 362. SPENCE BATE, Rep. Brit. Assoc. 1855. Ann. Nat. Hist. 2 ser. xix. p. 151. WHITE, Pop. Hist. Brit. Crust. p. 218. Cat. Brit. Crust, p. 61. JOHNSTON, Mag. Nat. Hist. viii. p. 673, figs. 72, 73. PROTO PEDATA. 39 Proto pedatum. DESMAREST, Consid. sur Crust, p. 276. Leptomera pedata. GOSSE, Mar. Zool. p. 131. fig. 224. Leptomera pedala. LATREILLE, Regne An. iii. p. 51. GUERIN, Iconogr. Crust, pi. xxviii. fig. 3. MILNE EDWARDS, Hist, des Crust, t. iii. p. 109. KROYER, Nat. Tidsk., iv. p. 607, pi. vii. figs. 13-23. DESMAREST, Consid. sur Crust. p. 276, pi. xlvi. fig. 3. Squilla ccaudata (Female). GRONOVIUS, Act. Helv. p. 439, pi. iv. figs. 8, 9, 10. Squilla ventricosa. MULLER, Zool. Dan. pt. ii. p. 20, pi. Ivi. figs. 1, 2, 3. THE animal is long, linear, cylindrical, and smooth, the head being intimately soldered with the first segment of the body. The eyes are small and round. The superior antenna? are about half the length of the animal; the flagellum being as long as the last two joints of the peduncle. The inferior antennas are about half the length of the superior, the flagellum being about half the length of the peduncle. The first pair of legs are small, having the hand acutely triangular, tapering to the finger. The palm is as long as the posterior margin, and armed with two or three rows of minute spines, its limit being defined by a sharp process, carrying one or two spines. The second pair of legs are at a considerable distance from the first, and situated near the middle of the second segment of the body. They are as long again as the first, and the hand is about twice as long and broad as that of the preceding pair. It is of a narrow oval form, having the palm more than half the length of the hand, defined by a sharp process, furnished with a small, stout spine ; it is excavated near the posterior limit, is wavy throughout its length, and armed with small processes tipped with spinules.* The third pair of legs are feeble * Dr. Johnston describes two varieties of this species — the first having the hands oval, with a single denticle at the base, the head rounded in front, and the branchial lamellae large and elliptical (to which the figures of Miiller 40 CAPRELLID^E. in appearance, and have the posterior margin of the penultimate joint armed with four radiating spines. The fourth pair are like the third, hut smaller, while the fifth are so much smaller and imperfect in their condition as to partake of a rudimentary character. They are, moreover, directed backward ; that is, contrary to the two posterior pairs, and therefore contrary to its normal con- dition. The two posterior pairs of legs are attached near together, in consequence of both being situated at the posterior extremity of their respective segments, the last of which is much shorter than any of the others. This single feature is sufficient to enable the observer to detect an animal of this genus, however otherwise damaged, since in Caprella, &c., the last two joints are always short, and hence the last three pairs of legs are always in close juxtaposition. The last two pairs of legs are longer than the others, and have the penultimate joint, for nearly two -thirds of its length, armed with two spines, opposed to the extremity of the finger which closes upon the preceding joint. The tail is rudimentary, consisting, when recent, of a cylindrical tube, without any limbs except two pairs of rudimentary, styliform appendages, situated near the extremity of the preceding segment, which probably fulfil the same office as their homologues in the male brachyurous Crustacea. We anticipate that the geographical distribution of this species will be ultimately found to be more general than our experience has yet ascertained. Tt was first taken as British by Montagu on the southern coast of and Montagu belong) ; and the second with the first pair of hands triangu- lar, somewhat lobed at the base, the wrist deeply serrated, the second pair of hands oval with two teeth at the base, and serrulate along the palm, head very obtuse in front, and the branchial lamelke smaller and cylindrical (to which all the Berwick specimens are referable). PROTO FED AT A. 41 Devonshire, where we have likewise found it. The Rev. Mr. Gordon has sent it to us from the Moray Frith ; so also have Mr. Gregor and Mr. Edward. The Rev. A. M. Norman has taken it in about forty fathoms one mile north of Whalsy lighthouse, in the Shetlands, and Milne Edwards records it from Denmark, where, in fact, the species was first discovered. Dr. Fleming found it at the Bell Rock, and Dr. Johnston in Berwick Bay, and Mr. R. Q. Couch at Mousehole Island, Cornwall. 42 CAPRELLll^E. A MPHIPODA . CAPRELLID^E. ABERRANTIA. PROTO GOODSIRII. Goodsir's Spectre Shrimp. Specific character. Superior antennae about one-third the length of the animal. Inferior antennae about one-half the length of the superior. Second pair of gnathopoda having the propodos large, arcuate above, palm excavated, and armed beneath, near the base and distal extremity, with a small tooth. Length § inch. Proto Ooodsirii. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. Cat. Amph. Brit. Mus. p. 350, pi. Iv. fig. 2. WHITE, Pop. Hist. Brit. Crust, p. 218. THIS species is a larger and more powerful-looking animal than P. pedata, from which it differs chiefly in the form of the second pair of hands. The superior antennae are about one-third the length of the animal, and the flagellum is about as long as the peduncle. The inferior antennae are about half the length of the superior — that is, scarcely reaching to the extremity of the peduncle of the latter. The first pair of legs have the hands elongate-ovate, broadest at the base, and nar- rowed at the extremity ; palm very oblique, slightly con- vex, minutely serrated, defined near the posterior extre- mity by an obtuse tooth. The second pair of legs have the hands very large, rounded above, and having the palm PROTO GOODSIRII. 43 concave, and frequently furnished with one or two sub- membranous hollow sacs. This latter feature (if our experience has not deceived us) is present only after death. We have observed this structure only in this family, and Dana has likewise figured it. The palm is armed near the base and distal extremity with two small teeth ; the finger is much curved, and its extremity alone impinges against the palm. The third pair of legs are rather longer than the second, and have the hand serrated and furnished with a few cilia. The fourth pair are like the third, but shorter ; the fifth are still shorter. The sixth and seventh are long and powerful, having the wrists, as well as the hands, furnished with uneven teeth and a few hairs. The tail is very rudimentary, and sup- ports in the male a single pair of rudimentary propoda. The branchiae are attached to the second, third, and fourth pairs of legs. This species has been named in honour of the lamented Mr. Goodsir, who promised fairly to distinguish himself in this branch of Natural History. It appears to be a northern species, since we have received it only from the Moray Frith, through the kindness of the Rev. George Gordon, from the Shetlands, where it was dredged by the Rev. A. M. Norman, and who also has found it on the coast of Durham. 44 CAPRELLID^. AMPHIPODA . CAPRELLID&. ABERRANTIA. Genus— PROTELLA. Protella. DANA, U. S. Explor. Exped. p. 812. SPENCE BATE, Cat. Amph. Brit. Mus. p. 351. Generic character. Cephalon confluent with the first seg- ment of the pereion. Pereion having the last two segments shorter than the preceding. Pleon rudimentary. Appendages to the cephalon well developed. Gnathopoda subchelate ; first two pairs of pereiopoda rudimentary, but having branchiae attached ; last three pair subequally long and robust. Anterior pair of pleopoda rudimentary, the rest obsolete. THIS genus differs from Proto in several important points : among the most conspicuous is the very rudi- mentary character of the third and fourth pairs of legs, which are represented by two small, uni-articulate, leaf- like plates. The penultimate segment of the body is as short as the last ; consequently, the last three pairs of legs are situated closely together at the posterior ex- tremity of the animal. Branchiae are attached to the third and fourth segments of the body, which, in the female, have also attached the plates belonging to the incubatory pouch. This genus was established by Dana, as possessing a character intermediate between that of Proto and Ca- prella, from which last it is distinguished by the character of the appendages of the intermediate segments of the body. Our knowledge of this genus is, as yet, confined to two species, one belonging to Britain, the other to South America ; therefore its geographical range cannot pro* perly be estimated. PROTELLA PHASMA. AMPHIPODA. ABERRANT! A. 45 CAPRELLID&. PROTELLA PHASMA. Montagu's Skeleton Shrimp. Specific character. Cephalon, without a rostrum, dorsally armed with a strong spine, originating in the posterior margin and directed upwards and forwards. First segment of the pereion dorsally and posteriorly armed with a strong tooth ; second segment similarly armed with a pair near the middle, and one near the posterior margin. Length rather more than half an inch. Cancer pliasma. MONTAGU, Trans. Linn. Soc. vii. p. 66, pi. vi. Caprella pliasma. Caprella phasma. jEgina longisplna. Protella lonyispina. LAMARCK, Syst. des An. sans Vert. v. p. 174. LATREILLE, Encyc. Met. p. 336, fig. 37. LEACH, Edin. Encyc. vii. p. 404. Enc. Brit. Suppl. 1, p. 426. SAMOUELLE, Ent. Comp. p. 105. DESMAREST, Consid. sur Crust. p. 278. MILNE EDWARDS, Hist, des Crust. iii. p. 108. WHITE, Cat. Crust. Brit. Mus. 1847. Cat. Brit. Mus. 1850, p. 60. Pop. Hist. Brit. Crust, p. 216. FLEMING in Edin. Phil. Jourh. viii. p. 297. JOHNSTON in Lou- don's Mag. Nat. Hist. viii. p. 669. RATHKE, Nov. Act. xx. p. 95. GOSSE, Mar. Zool. p. 223. R. Q. COUCH, Rep. Penzance, N. H. Soc. 1852, p. 96. KROYER, Nat. Tidsk. 2 ser. i. p. 476, 1844-6. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. 46 CAPRELLID.E. Caprella spinosa. GOODSIR, Edin. Phil. Journ. xxxiii. pi. 3, f. 1-3. WHITE, Pop. Hist. Brit. Cms. p. 197. Protella pkasma. SPENCE BATE, Cat. Amph. Brit. Mus. p. 351, pL Iv. fig. 4. Astacusphasma. PENNANT, Brit. Zool. iv. p. 27, Edit. 1812 (descr. only). THE head of this species is rounded in front, while a sharp, strong tooth, directed forwards as well as upwards, is situated upon the dorsal surface of the posterior mar- gin just where the head is contiguous with the first joint of the body, from which it can scarcely be identified. The first joint of the body is likewise furnished with a similarly strong, sharp-pointed tooth, situated near its posterior margin. The second segment carries near the centre a pair of strong teeth, one on each side of the dorsal median line, as well as a third, situated in the middle of the dorsal surface, near the posterior margin. The third and fourth segments exhibit rudimentary pro- cesses, probably representing teeth in similar positions. The superior antennae are rather more than half the length of the animal. The inferior antennae are about half the length of the superior. The first pair of legs are short ; the hand triangular ; the palm defined by a sharp process. The second pair are very much longer; the hand is large, elongate -ovate, the palm having a deep excavation near the anterior extremity, and defined by a prominent blunt tooth, surmounted by one or more spines. The finger articulates with the hand somewhat before the apex, so that a sharp process is produced above and beyond the articulation. The three posterior pairs of legs have the hands arcuate, the anterior margin being armed with small tubercles, surmounted by a spine, and defined by a strong process, which is surmounted by several short spines directed towards the extremity, and PROTELLA PHASMA. 47 corresponding with the extremity of the finger when closed. The female appears to differ in no essential character from the male, except in the possession of the ovigerous sac, the plates of which are attached to the third and fourth segments of the body. Col. Montagu, who was the discoverer of this species, was also the first to observe the love that exists between the parent and the offspring in this group of Crustacea. He writes, in the seventh volume of the Transactions of the Linnean Society : — " While examining a female in a watch-glass of sea-water under a microscope, we were agreeably surprised to observe not less than ten young ones crawl from the abdominal pouch of the parent, all perfectly formed, and moving with considerable agility on the body of the mother, holding fast by their hind claws, and erecting their heads and arms." This species is generally of a straw colour, delicately spotted with pink, fine specimens having the fingers banded with pink. As in all cornuted species, the spines on the head and the armature of the hands vary greatly. The animal represented by Goodsir under the name of C. spinosa has the occipital and dorsal horns of large size, as well as those upon the second pair of hands. This species appears to be more abundant in the southern parts of Great Britain than in the northern, although we have it recorded from one extremity to the other. It was first found in Devonshire by Col. Mon- tagu, and we have frequently obtained it in the neigh- bourhood of Plymouth. Mr. Gregor has sent it to us from the Moray Frith. Dr. Fleming obtained it from the Isle of Man, while Mr. Goodsir records it from the Frith of Forth. The Rev. A. M. Norman has taken it at Cullercoats, Northumberland, and Mr. R. Q. 48 CAPRELLIDjft. Couch among confervae, at Lariggan Rocks, Mount's Bay, Cornwall. In Norway it has been recorded by Rathke, and Kroyer has procured it at Christiana in Sweden. The following vignette represents one of these spectre- shrimps prowling through the deep recesses of a submarine graveyard, such as Clarence dreamt of when he said : — " Meth ought I saw a thousand fearful wrecks, A thousand men that fishes gnawed upon, Wedges of gold, great anchors, heaps of pearl, Inestimable stones, unvalued jewels, All scattered at the bottom of the sea. Some lay in dead men's skulls ; and in those holes Where eyes did once inhabit, there were crept (As 'twere in scorn of eyes) reflecting gems, That woo'd the slimy bottom of the deep, And mocked the dead bones that lay scattered by." CAPRELLA. 49 AMPHIPODA. CAPRELLIDA. 4BERRANTIA. Genus— CAPRELLA. Caprella LAMARCK, Hist, des Anim. sans Vert. p. 165. LEACH, Linn. Trans, xi. p. 363. MILNE EDWARDS, Hist, des Crust, iii. p. 105. KROYER, Nat. Tidssk. iv. p. 496. JEgitia. KROYER, Nat. TIDSSK. iv. p. 509. Podalirius. KROYER, Nat. Tidssk. 2 Scr. i. p. 283. Generic character. Cephalon confluent with the first seg- ment of the pereion. Pereion cylindrical, with the last two segments shorter than the two preceding; in the male the first two segments are long, in the female .they are shorter. Pleon rudimentary. Appendages of the cephalon normal. Gnathopoda subchelate ; in the male the second pair of gnathopoda articulates with the pereion near the middle or posterior extremity of the second segment, in the female at the anterior extremity of the same segment. First two pairs of pereiopoda wanting. Three posterior pairs subequal, and placed near to each other. One or two pairs of pleopoda rudi- mentary, the rest obsolete. THE head is confluent with the body. In the male the first segment of the body is longer than in the female, and the first pair of legs are always attached at the ante- rior extremity. The second segment is longer in the male than in the female, and we are strongly inclined to be- lieve that it increases in length with the age of the animal. The second pair of legs always articulate, in the female, at the anterior extremity of this segment ; whereas in the male they are affixed farther back, and generally posteriorly to the centre of the segment, and VOL. n. E 50 CAPRELLTD.E. sometimes quite at its extreme posterior limit. The three succeeding segments are generally of equal length, while the last two are always very short. Mr. Goodsir, who paid considerable attention to this family, says, in the " Edinburgh Philosophical Journal " for 1842 (vol. xxiii. p. 186) :— " The Caprella, like all the lower Crustacea, cast their skins often. Before the process commences, the animal lies for a considerable time languid, and to all appearance dead. At length a slight quivering takes place all over the body, attended in a short time with more violent exertions. The skin then bursts behind the head in a transverse direction ; and also down the mesial line of the abdominal surface. A few more violent exertions then free the body of the old covering. After this the animal remains for a consi- derable time in a languid state, and is quite transparent and colourless." The habits of these animals have not been much ob- served, living, as they do, amidst sea- weeds and zoophytes. They are active in scrambling from branch to branch, and are very likely to be overlooked. Mr. Goodsir, indeed, says that they are never seen to catch their prey, and " being slow and deliberate in their motions, they are not fitted for this mode of life;" to which we cannot sub- scribe, inasmuch as our experience would induce us to pronounce them to be active and energetic creatures. They generally grasp the objects to which they are attached by their strong posterior legs, and elevating themselves in an erect position, wave about their long antennae, probably in search of food. " Their usual mode of progression" is compared by Otho Fabricius (Faun. Gronl.), Montagu, Goodsir, and Gosse, " to that of the larvae of the Geometric moths." " They some- times," says Mr. Goodsir, " walk in this way for a consi- CAPRELLA. 51 derable time, and then suddenly stop, remaining perfectly motionless, not even moving their antennae." They seldom attempt to swim, and will, when placed in the water independently of anything to rest upon, generally drop listlessly to the bottom. Mr. Gosse says, in his pleasant Naturalist's Rambles on the Devonshire Coast, " I have seen a large red species swim, throwing its body into a curve like the letter S, with the head bent down and the limbs turned back, the body being in an upright position. It was a most awkward attempt ; and though there was much effort, there was little effect." Kroyer has separated from this genus two others upon characters which appear to us to be very doubtful. The tail in Caprella is rudimentary, and exists in a semi- membranous condition. The development of this abnor- mally rudimentary part is, within small limits, variable. Upon the degree of its development Kroyer has founded the genera Podalirius and JEgina. It is only after a care- ful consideration of the structure of the animals that we have arrived at the conclusion that the establishment of these two genera is unnecessary. The genus Cercops also of Kroyer is mainly distinguished from Caprella by the small terminal abdomen being six-jointed and styliferous, but the second pair of legs have a vesicle at the base, as in Proto. The geographical distribution of this genus is very universal, since species are recorded from almost every locality that has been visited by the carcinologist. E»> .» 52 AMPHIPODA. ABERRANTIA. CAPRELLID.E. CAPRELLID^E. CAPRELLA LINEARIS. Pennant's Skeleton Shrimp. Specific character. Cephalon and pereion smooth and unarmed. Second pair of gnathopoda in the male having the propodos with the palm armed with a single tooth, in the female with two small tubercles, and in both defined by a short process armed with a spine. Length \ inch. Cancer linearis. LINNAEUS, Syst. Nat. ii. p. 1056 ? Herbst. Krabben, ii. pi. xxxvi. fig. 9, 10. Caprella linearis. MILNE EDWARDS, Hist, des Crust, iii. p. 106. DESMAREST, Consid. sur Crust, p. 278. LA- TREILLE, Hist. n. Crust, et Ins. vi. p. 324, pi. Ivii. fig. 2-5. JOHNSTON, Mag. Nat. Hist, viii. p. 672, fig. 71. Risso, Crust de Nice, p. 130. GTOODSIR, Edin. New Phil. Journ. xxxiii. p. 190, pi. iii. fig. 8. R. Q. COUCH, in Rep. Penzance, Nat. Hist. Soc. 1852, p. 98. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. Cat. Amph. Brit. Mus. p. 353, pi. Iv. fig. 7. WHITE, Cat. Brit. Crust, p. 59. Pop. Hist. Brit. Crust, p. 214. CAPRELLA LINEARIS. 53 Cancer (Astacus) atomos? PENNANT, Brit. Zool. ed. 1777, iv. p. 17, pi. xii. fig. 32. EASIER, Opusc. Subs. pi. iv. fig. 2. Cancer (Astacus) punctate. Risso, Crust, de Nice, p. 130. Hist. Nat. Eur. merid. v. 102. Oniscus scolopendroides. PALLAS, Spic. Zool. ix. p. 78, pi. iv. fig. 15. Squilla quadrilobata 1 MULLER, Zool. Dan. ii. pi. xxxvi. fig. 4-6, male ; iii. pi. cxiv. fig. 11, 12, female. THIS species must be considered as the type of the genus. It has the head and back unarmed. In the male the first segment of the body is longer than in the female, as is also the second segment ; the three succeed- ing are subequal in length, and a little shorter than the second ; the last two are but half the length of the pre- ceding. The superior antennae are about half the length of the animal, the peduncle being rather longer than the flagellum. The inferior antennae are about half the length of the superior, reaching scarcely to the ex- tremity of its peduncle. The first pair of legs are short, and articulate with the first segment of the body at the anterior extremity : the hand is ovate, the palm very oblique, straight, ciliated, and defined by a process or tooth : the finger is serrated, and slightly curved. The second pair of legs are a little longer than the first, and articulate with the second segment just at the centre, but in the female a little more anteriorly ; the hand is long-ovate, having the palm defined by a process or tooth, tipped with a spine, and armed with a tooth situated anteriorly to the centre, and just before which is a square-angled tooth or process. The last three pairs of legs are short, robust, and have the hand excavated in front, and armed with two small spines, which antago- nize with the extremity of the finger when closed. The incubatory pouch is an appendage which is de- veloped when required for the purpose of carrying the ova, as shown in the two figures given below. It con- 54 CAPRELL1DJE. sists of four plates, two attached to the third, and two to the fourth, segment of the body, arising upon the under surface and the inside of the branchiae. We have observed this organ in various stages of development, from the small pedicle to the shell-like scale. The habits of this animal are curious, and repay the naturalist for some patient observation. We have already noticed the parental affection existing between animals in this order and their offspring. In more than one species of this genus similar observations have been made. As soon as the young are old enough to enjoy a separate state of existence they quit the protection of the ovi- gerous pouch in which they have been nurtured, and, passing out, climb, gipsy-like, to the back of their mother, where they may be seen holding on in every con- ceivable attitude. Mr. Goodsir, in writing of this display of maternal care, says : — " On one occasion, while examining a female Caprella under the microscope, I found that her body was thickly covered with young ones. They were firmly attached to her by means of their posterior feet, and they were resting in an erect posture, waving about their long antennae with great activity," as represented in the vignette given in a subse- quent page. In the national collection is preserved a specimen of an exotic species in which death has not separated the parent from the offspring. They may still be seen attached, as if climbing from the incubatory pouch to the back of the parent. They live mostly amongst weeds and submarine growths, and " are as much at home in the tree-like zoophyte as a family of monkeys in their arborial bowers ; and, indeed, their agility, as they run from branch to branch, catching hold of a twig just within reach and CAPRELLA LINEAR! S. 55 pulling themselves in an instant up to it, then stretching out their long arms in every direction, strongly reminds one of the spider-monkeys of South America." * In 1854 Mr. P. H. Gosse sent us some minute speci- mens of Caprellce which he had found in considerable numbers on the rays of a small specimen of Solaster pap- posa, which we have always considered as the young of Caprella linearis, with which they agree in their general character ; but the second segment of the pereion is not longer than the first and the superior antennae are scarcely longer than the inferior ; it is a remarkable fact that some of the specimens, being females, are fur- nished with the incubatory pouch. As these animals (of which we give figures as a vignette on the next page) are only one-tenth of an inch in length, we must either con- clude that they are imperfectly-developed specimens of C. linearis, and that they are endowed with the capability of reproduction before they have attained to their adult form and dimensions ; or that they are a species distinct in themselves, exhibiting the character of an imperfectly- developed specimen of C. linearis. Moreover, it is singular that they should have been found in great abundance in this solitary instance, for we are not aware of any having been similarly taken in any other instance. If they be young animals we must assume them to have been of a single brood ; but if so, it is a curious feature in their history that the brood should remain associated until the females were old enough to carry ova, and that this latter circumstance should occur while the animals were still so small. Since the above has been written, Mr. Norman has * Gosse's Rambles of a Naturalist in Devonshire. 56 CAPRELLIDJS. sent us several specimens that resemble the male of this small variety. These vary in size, and we should not hesitate to pronounce them to be the young of C. linearis ; amongst them there is not a single specimen furnished with the incubatory pouch, although some are larger than those taken by Mr. Gosse. CAPRELLA LOB AT A. AMPHIPODA. ABERRANTIA. 57 CAPRELLID^E. CAPRELLA LOBATA. Specific character. Body unarmed except by a few minute tubercles occasionally present, especially upon the dorsal surface of the three posterior segments of the pereion. First segment of the pereion long ; second scarcely longer than the first. Second pair of gnathopoda having the propodos long- ovate ; palm defined by one, and armed with two teeth, the anterior being less distinct than the posterior. Length f inch. Squilla lobata. MULLER, Zool. Dan. Prod. 197, No. 2359. 0. FABR. Fauna Grb'nl. p. 248. SAMOUELLE, Ent. Comp. p. 106. Caprella lobata. GUERIN, Iconogr. R. An. Crust, pi. xxviii. fig. 2. KROYER, Voyage en Scand. pi. xxv. fig. 3a. STIMPSON, Nat. Hist. Invert. Grand Manan, p. 44. THOMPSON, Ann. Nat. Hist. xx. p. 244. SPENCE BATE, Cat. Amph. Crust. Brit. Mus. p. 354, pi. Iv. fig. 8. Ann. Nat. Hist. 2 ser. xix. p. 151. Squitta quadrttobata. MULLER, Zool. Dan. t. 114, fig. 11, 12. j/Bgina lonyicornis. KROYER, Voy. en Scand. pi. xxvi. fig. 3. Caprella Icevis. G-OODSIR, Edin. New Phil. Journ. xxxiii. p. 189, pi. iii. fig. 4. WHITE, Pop. Hist. Brit. Crust, p. 215. Hist. Brit. Crust, p. 60. Caprella lincaris. LEACH, Edin. Enc. vii. p. 404 ? IN this species the animal is generally smooth, but we have occasionally seen specimens which have a few minute tubercles on the back, those most important and 58 CAPRELLID.E. constant being on the last three segments of the body, and such are figured by Kroyer. The head is rounded in front, and occasionally surmounted by a minute tubercle. The first segment of the body, which is confluent with the head, is rather long. The second is rather longer, while the three succeeding are somewhat shorter, and subequal in length. The superior antennae are not half the length of the animal. The inferior scarcely reach beyond the distal extremity of the second joint of the peduncle of the upper. The first pair of legs articulate with the body at the anterior extremity of the first seg- ment of the body. The second pair of legs articulate with the body behind the middle of the second segment : the hand is long and oval, the palm being distinctly defined by a strong tooth, and armed also near the middle with two others, the anterior of which is fre- quently less distinctly apparent than the posterior. All the remaining parts bear a very near resemblance to those of C. linearis. Dr. Leach describes this species (under the name of C. linearis) as being, when alive, of a brown colour, in- clining to cinereous, beautifully spotted with rust colour. All the specimens that we have examined of this species are certainly males, and we have a strong convic- tion that they are but fully-developed males of C. linearis, from the fact that the specimens which we have described as males of Caprella linearis only differ from those of C. lobata in having the first and second segments of the body shorter, these two segments being subject to vary in length, and probably increasing with age. Furthermore, we have never been able to determine the female of C. lobata. C. lobata is, moreover, generally associated with C. linearis, and will probably be found to exist all round the CAPRELLA LOB AT A. 59 coasts of Europe. In Great Britain it has been obtained at Kames Bay, N. B., by Mr. Robertson ; in the Moray Frith by Mr. Edward ; at Cullercoats it was taken by the Rev. A. M. Norman, and we have taken it at Ply- mouth. Specimens from the Frith of Forth are preserved in the British Museum collection. The accompanying vignette represents a female Caprella carrying her offspring upon her back, as described at page 54. 60 CAPRELLID^E. AMPHIPODA. ABERRANTIA< CAPRELLID^E. CAPRELLA ACUTIFRONS. Specific character. Cephalon in both sexes anteriorly surmounted by a strong tooth directed forwards. Second pair of gnathopoda having the pro- podos with the palm deeply waved, and denned by an obtuse angle armed with a spine ; limbs very robust. Length ^ inch. Caprella acutifrons. LATREILLE in N. Diet. d'Hist. Nat. 2nd Edit. vi. p. 433 (1816), DESMAREST, Consid. sur Crust, p. 277. MILNE EDWARDS, Hist, des Crust, iii. p. 108. WHITE, Pop. Hist. Brit. Crust, p. 216. Cat. Brit. Crust, p. 60. SPENCE BATE, Cat. Amph. Crust. Brit. Mus. p. 356, pi. Ivi. fig. 6. VAN BENEDEN, Re- cherches sur la Faune littorale de Belgique, p. 145, pi. xvi.bi" fig. 9-11. PENNANT, Brit. Zool. iv. pi. xiii. fig. 13, 2nd ed. 1812 (very bad). STEW. Elements, ii. p. 317. LEACH, Edin. Encyc. vii. p. 404. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. JOHNSTON in Ann. Nat. Hist. viii. p. 670. R. Q. COUCH in Report Penzance, Nat. Hist. Soc. 1852, p. 97. IN this species the male and female do not appear to differ very materially. The head is surmounted by an anteriorly-directed horizontal tooth, but the rest of the body is smooth. In the male the first segment of the body is scarcely longer than in the female, and the second segment is not much longer than in the female, nor is it longer than the third or fourth segments. The third and Cancer (Astacus) atomos ? Caprella Penantis. Caprella Peniwmtii. CAPRELLA ACUTIFRONS. 61 fourth, which in the female carry the ovigerous plates, have, in the male, the lateral walls (coxae) produced into lateral plates, which are produced anteriorly to a point. The superior pair of antennae are about two-thirds the length of the animal, the flagellum is shorter than the peduncle, and each articulus is infero-distally produced, and furnished with cilia. The inferior antennae are about the length of the peduncle of the superior, termi- nating in a short flagellum, which consists of a long and a short articulus. The first pair of legs are short, but the form of the hand resembles that of the second. The second pair of legs are longer than the first. In the female they articulate with the extreme anterior limits of the second segment, but in the male they articulate a little posteriorly. The hand, in the male, is ovate, tapering to the distal extremity ; the palm is waved, and defined by a strong tooth, armed with a stiff spine. In the female the palm is less distinctly waved and de- fined. The three posterior pairs of legs are short and robust. The only animal that we have seen alive was covered with numerous points or fine hairs. It was of a reddish colour, shaded off into green. This species appears to be one of the least dispersed in the British seas, and our observations have consequently been the more restricted. It was found by Dr. Leach on the Devonshire coast, and it has since been taken in Plymouth Sound by Mr. Boswarva. " Not uncommon among Corallines in Mount's Bay."— Mr. R. Q. Couch. Van Beneden states, that it is found in great abundance on the shores of Belgium, in the middle of tufts of con- fervae along with Tanais, upon the carapace of Chelonia my das. 62 CAPRELLID.E. This species appears to have a near representative in different parts of the globe. It differs but little from C. geometrica of the United States, and is distinguishable in the thickness of the body only from C. robusta from Rio Janeiro. It closely resembles C. nodosa from the Mauritius, and also a species recently sent to us by Mr. Taylor, that we take to be identical with C. geometrica, and which he procured in great abundance from amongst the weeds at the bottom of an old yacht which had been lying undisturbed for about two years in the harbour of Hong Kong. The vignette below represents a Gower Cockle Girl. CAPRELLA HYSTRIX. AMPHIPODA. ABERRANT!^. 63 CAPRELLID^E. CAPRELLA HYSTRIX. Specific character. Tuberculated along the dorsal surface, the tubercles increasing posteriorly. Second pair of gnathopoda having the propodos ovate ; palm convex, defined by a blunt process surmounted by a spine. Length f inch. Caprella Hystrix. Caprella acuminifera. KROYER Nat. Hist. Tidssk. iv. 603. pi. viii. fig. 20-26. Voy. en Scand. pi. xxiv. fig. 1 ? MILNE EDWARDS, Hist, des Crust, t. iii. p. 107, pi. xxxiii. fig. 21. SPENCE BATE, Cat. Amph. Brit. Mus. p. 359, pi. Ivi. fig. 11 (not of LATREILLE and DESMAREST).. THIS species is tuberculated throughout the entire length of the animal, the tubercles increasing in size towards the posterior extremity of the body. The head is slightly angulated on the crown. The first segment of the body is short ; the second is longer, and of the same length as the third, fourth, and fifth. The sixth and seventh are shorter. The superior antennae are less than half the length of the animal ; the inferior are not longer than the peduncle of the superior. The first pair of legs are small ; the second articulate near the centre of the second segment of the body, but in the 64 CAPRELLID^E. female (figured above) they articulate quite at the ante- rior extremity. This is the only reliable distinction that we have been able to discover between the two sexes. The hand in this pair of legs is ovate, the palm convex, being defined by a process surmounted by a spine. The palm is emarginate near the posterior extremity, and waved a little anteriorly. We consider this species to be identical with that figured by M. Milne Edwards in the place cited, as also, probably, with the (7. Hystrix of Kroyer, although the description of the head given by the former author, " ovalaire, courte et arrondie en dessus," seems to have been derived from C. acanthi/era, and his observation that the penultimate joint of the last three pairs of legs is narrow and without a tooth on the inner edge, disagrees with our species (although agreeing with Kroyer's details of the legs of C. hystrix). Unfortunately M. Milne Edwards is unable to clear up this difficulty, the speci- men from which he drew his figure not having been preserved. Considering the C.acuminifera of Latreille to be identical with C. acanthifera of Leach, we have been obliged to take up Kioyer's name for the present animal, although not quite agreeing with his description as above noticed. We have received specimens of this species from Millport, sent to us by Mr. Robertson ; from Northum- berland, where it was found by the Rev. A. M. Norman, and we have taken it in the neighbourhood of Ply- mouth. CAPRELLA ACANTHIFERA. AMPHIPOLA. ABERRANTU. 65 CAPRELLIVM. CAPRELLA ACANTHIFERA. (Skull-headed Skeleton Shrimp.) Specific character. Cephalon posteriorly and dorsally vaulted. First seg- ment of the pereion short ; second, third, and fourth subequally long, sur- mounted by three large dorsal tubercles ; fifth, sixth, and seventh segments short, each surmounted by two sublateral parallel tubercles. Second pair of gnathopoda having the propodos large in the male, rounded above and very concave below, the palm defined by a prominent tooth ; in the female the palm is slightly convex and the dorsal tubercles are less prominent. Length 58S of an inch in the male, and 57g in the female. Puce de mer arpenteuse. DE QUERONIC, Mem. Math, et Physiq. Acad. Sci. Paris, t. ix. p. 329, fig. A B. LEACH, Edin. Ency. vii. p. 404 (not of Johnston and Couch). W. THOMPSON, Ann. Nat. Hist. xx. p. 245. WHITE, Cat. Brit. Crust, p. 60. Pop. Hist. Brit. Crust, p. 215. SPENCE BATE, Cat. Amph. Crust. Brit. Mus. p. 359, pi. Ivi. fig. 11. Caprella acanthifera. Caprdla calva. VOL. II. 66 CAPRELLID^E. Caprella acwninifera. LATREILLE, in Nouv. Diet. d'Hist. Nat. 2nd Edit, vi. p. 433. DESMAREST, Consid. Crust, p. 277 (not of Johnston). SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. THIS species may readily be detected from any other by the peculiarly vaulted or skull-like head, together with the tuberculated character of the body. The first segment of the body is short. The three next are longer than the first, equal to each other, and surmounted by three dorsal blunt teeth, or tubercles. The two anterior, immediately over the articulation of the second pair of legs, are sublateral and parallel. The third is central, and situated upon the posterior margin. The last three seg- ments are short, and each is furnished with only two sublateral parallel tubercles, which are surmounted by nu- merous small, bead-like tubercles. The superior antennae are not half the length of the animal. The inferior antennae are not longer than the peduncle of the superior. The first pair of legs are small, the hand being ovate and the palm slightly convex and imperfectly defined. The second pair of legs articulate with the second seg- ment of the body, posteriorly to the centre. They have the hand in the male very large, rounded on the back, and hollow below (in some specimens we have seen inflated membranous sacs filling the palm), being defined posteriorly by a sharp tooth, and armed anteriorly with a small point that marks the position where the lateral walls of the palm unite together anteriorly. The finger is much curved, and armed with two obtuse teeth upon the inner margin. The three posterior pairs of legs are of equal length, and adapted for prehensile use. In the female the tubercles upon the back are less conspicuous than in the male, and the second pair of legs have the hand smaller, of an oval form, the palm being slightly convex, defined by a small process, armed with CAPRELLA ACANTH1FERA. 67 one or two short, stiff spines. In the young the hand is nearly of the same form as that of the female, but the palm is only imperfectly, if at all, defined. Between this last and that of the male above described, we represent in our plate four figures, exhibiting various degrees of development in different individuals of the same species.* This species was first excellently figured by M. De Queronic, as above referred to, from a specimen found amongst the branches of a Fucus, covered with coral- lines, in the Bay of Loc Mariaker, on the coast of Brittany. It has been taken at Plymouth by Mr. Barlee on Drake's Island at low water spring-tides, as well as dredged by ourselves in Plymouth Sound. Mr. Edward has sent it to us from Banff, the Rev. A. M. Norman from Northumberland, and we have received it from Mr. Robertson from Millport. Specimens are also in the Belfast Museum Collection, obtained by the late W. Thompson, Esq., who found it amongst Corallina officinalis, in shallow pools between tide-marks, at Spring- Vale, County Down, in July, 1846. It is also in the Bell Collection at Oxford, taken by the Rev. J. Gordon in the Frith of Forth. * In the British Museum is preserved a series of this species, to one of the individuals of which the specific name C. acanthi/era is attached in the hand- writing of Dr. Leach, whose description, — "Back, especially the hinder part, spiny; inner edge of the second pair of hands lunate -excavated," — is so short and insufficient as to have led Mr. Spence Bate into the idea that the fol- lowing species was the true C. acanthi/era, and the present one, consequently, undescribed. Dr. Leach found his species not uncommon on the Devonshire coast, and forwarded specimens to Latreille with the MS. name of C. acumi- nifera, which was adopted by Latreille and Desmarest, the former of whose descriptions is evidently taken from a male of C. acanthi f era. Both these names have been misapplied by Johnston and R. Q. Couoh to the cornuted females of the following species. FH A 68 AMPHIPODA. ABERRANTIA. CAPRELLID^E. CAPRELLID^E. CAPRELLA TUBERCULATA. Specific character. Male. — Cephalon not lobed. First two segments of the pereion long and smooth ; the five last shorter and dorsally tuberculated. Second pair of gnathopoda having the propodos long, pubescent; palm defined by a strong tooth. Length 4 inch. Female. — Cephalon surmounted by a tooth, and the pereion dorsally tuber- culated. Second pair of gnathopoda defined by a small tooth. Length £ inch. Caprella tuberculata. GUERIN, Icon. R. An. Crust, pi. xxviii. fig. 1. GOODSIR, Edin. New Phil. Journ. xxxiii. p. 188, pi. iii. fig. 6. W. THOMPSON, Ann. Nat. Hist. xx. p. 244. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 151. WHITE, Cat. Brit. Crust, p. 60. Pop. Hist. Brit. Crust, p. 215, pi. xi. fig. 5. Fern. Caprella acuminifera. JOHNSTON, Mag. Nat. Hist. vi. p. 40. fig. 7a (not of Latreille and Desmarest). Fern. Caprella acanthifera. JOHNSTON, Mag. Nat. Hist. viii. p. 671, fig. 70. R. Q. COUCH, Rep. Penzance, Nat. Hist. Soc. 1852, p. 96 (not of Leach). SPENCE BATE, Cat. Amph. Brit. Mus. p. 360. pi. Ivii. fig. 2. CAPRELLA TUBERCULATA. 69 THE males are much larger than the females. The head, instead of being armed with a tooth, is furnished with a minute tubercle. The first two segments of the body are very long, and smooth ; the second somewhat hirsute. The third, fourth, and fifth are shorter than the preceding, and subequal in length ; these are all tuberculated upon the dorsal surface, as are also the sixth and seventh segments. The tubercles, which are very insignificant upon the third segment, increase in size posteriorly, and are very conspicuous upon the three last segments. The superior antennae reach but little beyond the first segment of the body. The first joint of the peduncle is about the same length as the third, but the second joint is much longer than either. The inferior antennae reach to the extremity of the second joint of the peduncle of the superior. The first pair of legs are very small, and situated quite at the anterior extremity of the first segment of the body, therefore appear to be attached to the head. The second pair of legs articu- late with the second segment of the body at its posterior extremity. The hand is nearly as long as the second segment., and hirsute upon the upper margin and palm. The palm lies nearly parallel with the upper margin for more than half the length of the hand, where it is defined by a strong tooth or process. The finger is furnished upon the inner margin with an obtuse tooth or pointed tubercle. The last three pairs of legs are short and robust. In the female the head is surmounted by a strong tooth, directed upwards and forwards. The first segment of the body is short; the second much longer, and tubercu- lated ; the five remaining segments are tuberculated, the tubercles increasing in size posteriorly. The second pair of legs articulate near the anterior extremity of the 70 CAPRELLID^l. second segment of the body. The hand is ovate, the palm straight, and defined by a small denticle. We have received this species from Guernsey, where it was taken by the Rev. A. M. Norman, and from Mill- port, N.B., where it was captured by Mr. Robertson. A considerable number were found by Mr. T. L. Couch in the crevices of a crab-pot buoy thrown on the coast at Polperro during a heavy gale in 1854-, and Mr. R. Q. Couch obtained the female at Mount's Bay, in Gwavas Lake, and off St. Michael's Mount, among confervas. Specimens from the Frith of Forth are contained in the British Museum Collection. In the male of this species the form of the palm is very liable to vary from the character as exhibited in the female to that of the male, as above described. It is not hastily that we have come to the conclusion that the two animals represented above are but sexes of one species. The animals are from the same locality, and their distinctive characters do not appear to have a higher value than such as indicate the sexes of one and the same species. We have been induced to identify it with Goodsir's C. tuberculata by the pointed tooth upon the head, rather than to associate the latter with C. hystrix (acuminiferd), which also may possibly be but a variety of this same species. CAPRELLA ^QUILIBRA. AMPHIPODA. ABERRANTIA. 71 CAPRELLID^E. CAPRELLA ^EQUILIBRA. Specific character. Male.— Body smooth. First and second segments of pereion very long, equal to half the length of the animal. Second pair of gnathopoda articularly at the posterior extremity of the second segment ; propodos long-ovate ; palm subparallel with the upper margin, armed anteriorly with a large triangular tooth or process, and a small denticle immediately posterior to the process. Length f inch. Caprella cequilibra. SPENCE BATE, Cat. Amph. Crust. Brit. Mus. p. 362, pi. Ivii. fig. 5. Caprella equilibra. SAY, Journ. Acad. Philad. i. p. 391. Caprella Januarii. KROYER, Nat. Tidssk. iv. p. 499, pi. vi. fig. 14-20. Voy. en Scand. pi. vi. fig. 15. DANA, U. S. Explor, Exped. p. 819, pi. Iv. fig. 2. 72 CAPRELLID^. THE body of this animal is smooth. The head is round and unarmed. The first segment of the body is very long, cylindrical, and slender. The second seg- ment is as long as the first, and resembles it, except that as the first gradually lessens in diameter pos- teriorly, the second as gradually increases posteriorly, and is armed inferiorly, in the ventral median line, with a long straight tooth, between the articulations of the second pair of arms. These two segments, with the head, occupy half the length of the animal. The remaining five segments of the body are, therefore, shorter than in the majority of the species of this genus. The superior antennae are not half the length of the animal; the first joint of the peduncle is longer than the head ; the second more than twice the length of the first ; the third about half the length of the second, and does not taper at the extremity : the flagellum is about half the length of the third joint of the peduncle, and half the diameter at the base. The inferior antennae are not half the length of the superior. The first pair of legs are very small, and situated at the extreme anterior limit of the first segment of the body, therefore close to the head. The second pair of legs articulate with the second segment near the posterior extremity, conse- quently are situated about the centre of the animal, a circumstance from which we presume that Say gave the animal its specific name ; the hand is long, and some- what oval in its general form, but the palm, which is defined by a small tooth, is straight, running nearly parallel with the upper margin, and occupying about two-thirds the entire length of the hand, which is more than half the length of the second segment of the body ; the palm is armed at the anterior extremity with an acute tubercle or short tooth and a small denticle (which, CAPRELLA ^QUILIBRA. 73 Say says, is not constant), situated immediately posterior to the process. The last three pairs of legs are very short. Having had the opportunity of comparing our British specimens with that presented to the British Museum by Mr. Say, we are enabled to assert their identity, and we are not able to detect any character by which this species differs from C. Januarii, as described by Dana and Kroyer. We have also seen specimens from Hong-kong, and are unable, by the closest observation, to discover any difference between them. The geographical range of this species is, therefore, very great. In our own country we took it first amongst weeds attached to one of the buoys in Plymouth Sound. It has since been sent to us from Seaham by the Rev. A. M. Norman, who has also taken it at Cullercoats. But Kroyer's type came from Rio Janeiro, while Dana's specimens were procured from an anchor in from ten to twelve fathoms of water, also at Rio Janeiro. Mr. Harington has sent specimens to the British Museum, which he procured at Hong Kong, and Say found his specimens "very common in the bay of Charleston, particularly at Sullivan's Island, on the two species of Gorgonia, so common in the salt-water creeks of the southern coast." 74 CAPRELL1D.E. A MPHIP ODA . CA PEELLID^E. ABERRANTIA. CAPRELLA SPINULATA. Specific character. "Long and slender; head deeper than the other annulations. Head without a spine, but all the other annulations with one or more dorsal spines." Caprella spinulata. R. Q. COUCH, in Report Penzance Nat. Hist. Soc. 1852, p. 98. " LONG and slender. The head is larger than the next articulation, and without a spine ; the occipital articula- tion with a spine near its posterior margin ; and there is one on the next ring above the branchiae. There are two on the third, one above the branchiae, one near its posterior margin, and one in the centre of each of the others. Superior antennae as long as the body; basal joint small ; the second about four times as long as wide ; the third long and slender, and slightly enlarged towards its distal extremity, the last multi -articulate and ciliated. The inferior antennae much smaller than the others. At the lower part of the head two pedi-palpi, small and bifid at their extremities. The hand very large ; move- able joint long, slender, and hooked, and at its point, when bent, touches a spine on the hand." Taken by Mr. R. Q. Couch (whose recent death we have to deplore) in a pool among confervae, Lariggan Rocks, Mount's Bay, Cornwall, from whose description in the work above quoted we make this extract, regret- ting that we are unable to give a representation of this species. CAPRELLA TYPICA. 75 A MPHIPODA . CAPREL LIDJ!. ABERRANTIA. CAPRELLA TYPICA. Specific character. Body entirely smooth, and destitute of spines in both sexes. Second segment of the body short and deep. Second pair of gnathopoda with the hand large and curved, armed at the base of the palm (denned by a strong obtuse tooth) with a robust recurved spine. Antenna? moderately long and slender ; hind legs slender, with the hand simple. Length \ inch. Podalirius typicus. KROYER, Nat. Tidssk. 2nd Ser. i. p. 283. Voy. en Scand. pi. xxv. fig. 1 a — 1. SPENCE BATE, Cat. Amph. Brit. Mus. p. 354, pi. Ivi. fig. 2. THIS species has been formed by Kroyer into a sepa- rate genus, named Podalirius, in consequence of the very rudimental condition of the abdominal portion, of which none of the appendages are developed (Fig. P). It resembles C. linearis, but is more robust, the head and second segment of the body being deeper and shorter than in that species. The antennae are slender : the superior in the male are nearly twice as long as the inferior, the peduncle of which scarcely reaches to the extremity of the second joint of the superior; the flagel- lum of the latter being composed of very few articuli. In the female the peduncle of the lower antennae appa- rently extends as far as the extremity of the peduncle of the superior, which is, however, mutilated in our unique 76 C A PRELUDE. specimen of this sex. The males are also at once distin- guished by the peculiar form of the hand of the second pair of legs, which is of large size, strongly curved on its fore margin, whilst the posterior, or palm, is exca- vated ; its distal extremity broadly but obliquely trun- cate, whilst its base is armed with an obtuse point, antagonizing with the tip of the finger, followed by a strong bent and recurved tooth. The first pair of legs are small, and the hand oblong-ovate ; this is also the form of the hands of the second pair of legs in the female, but the base of the palm is defined by a conical point near to the base of the joint. Our specimens (like those of Kroyer) have also lost the antepenultimate pair of legs, but in the two posterior pairs the joints are slender, naked, and destitute of spines or points, so as to appear quite simple. Several specimens of this species, collected by the Rev. J. Gordon in the Frith of Forth, exist in the Bell Collection of Crustacea, recently presented to the Uni- versity Museum of Oxford by Professor Westwood. They were obtained upon a shell brought up on a had- dock line on the 18th September, 1855. CYAMIDJE. 77 Fam. III.— CYAMID^i. Body flat. Cephalon cylindrical, tapering, anchylosed with the first segment of the pereion. The latter broad, depressed, with the segments laterally wide apart. Pleon rudimentary. Eyes posterior to the superior antennae, of which the flagellum is indistinctly articulated. Inferior antennae minute, inserted between the upper pair and the labrum. Gnathopoda subchelate. Pereiopoda flat, broad, and furnished with strongly -hooked dactyla, wanting to the third and fourth segments of the body, which are furnished with elongated branchiae. This family consists of a single genus, the species of which are parasitic upon the cetaceous animals. They are of moderate size, and are able, by means of the strong hooks with which their legs are terminated, to affix them- selves firmly to their prey. The head is small, oblong, and cylindrical, soldered to the first segment of the body, which is dilated at its sides, giving this part of the animal a pear-shaped appearance. The antennas are affixed to the anterior and superior extremity of the head. The upper pair are of moderate size ; the peduncle composed of three nearly equal-sized joints, followed by a small, indistinctly -articulated flagellum. The inferior pair are very small, and terminate in a small conical, apparently uni-articulate flagellum. Immediately beneath these lat- ter appendages is a small tubercle, which is homologous with the olfactory organ of the normal Amphipoda. The mouth is small, and placed at the infero-anterior extremity of the head : it consists, according to Savigny, of a 78 CYAMID^l. labrum, rounded at the sides, but emarginate in front; a pair of mandibles, bifid and denticulated at the tip, but destitute of a palpus ; a first pair of maxillae, com- posed of a single lobe ; a second pair of maxillae, much smaller than and inserted between the first pair, upon a common base, and each bearing a very minute two-pointed palpus ; a labium, composed of two outer lobes and two inner minute ones (representing the four maxillae), and a large maxillary outer labium, furnished with a pair of five-jointed palpi. Independent of the first articulation of the body, sol- dered to the head, the animal consists of six flattened segments, of which the middle ones are the broadest. They are separated widely from each other at the sides, and the last is terminated by a minute rudimental tail. The segment attached to the head supports on its under- side a pair of small legs, generally folded beneath the body, composed of four joints, terminated by a subcheli- form hand and a slender, curved finger. The following segment of the body bears a large and powerful pair of legs, although they possess one joint fewer than the hinder pairs. The hand is broad and flattened, and the finger curved and acute at the tip. The third and fourth segments of the body are destitute of legs, but their place is supplied by a pair of elongated, cylindrical, branchial appendages, in some species being as long as the legs themselves, generally turned over the back of the animal. Sometimes these are simple, but in other cases they are double, and at their base in the male is to be observed one or two small corneous points. In the female these two segments of the body bear two large ovigerous scales, affixed at the base of the four branchial appendages. The fifth, sixth, and seventh segments of the body respectively bear a pair of legs nearly similar in 79 shape and size to those of the second segment, but com- posed of five joints, the coxae being soldered to the seg- ments to which they are attached. The tail is very minute and rudimental : on its underside in the male are perceived two pairs of slender, deflexed, horny append- ages ; each of the two preceding segments being armed on the ventral surface with a pair of strong spines. In the female the antepenultimate segment of the body is fur- nished on its under-surface with two small transverse valves, uniting into a tubercle, which closes the orifice of the generative organs. The analogy which these animals exhibit with the Pediculi among hexapod insects, and with Pycnogonum amongst the Arachnida, merits attention. MEN TARRING A BOAT. 80 A MPH1P ODA . C YA MID^E. ABERRANTIA. Genus— CYAMUS. Cyamus. LAMARCK, Syst. d. Anim. sans Vert. p. 166. LATREILLE, Hist. Nat. Crust., &c., vi. p. 328. DESMAREST, Cons. Crust. p. 279. Larunda. LEACH, Trans. Linn. Soc. xi. p. 363. SAMOUELLE, But. Comp. p. 106. Panope. LEACH, Edin. Encyc. vii. p. 404. Generic character. Head and first segment of the body fused into a pear-shaped mass. Eyes small and vertical. Segments of the pereion with the sides horizontally dilated ; the legs attached to the postero-lateral margins ; five pairs of strongly subcheliform legs, wanting in the third and fourth segments, which are furnished with two pairs of branchial appendages, long and filiform. Pleon rudimental. THESE animals affix themselves by means of their strong legs upon the rough portions of the bodies of cetaceous animals upon which they feed ; the different species appear to affect particular portions of the bodies of these animals, some being found massed together upon the head, others are more erratic, or affix themselves to the fins, organs of generation and folds of the flesh. The males are larger than the females, upon which they affix themselves by means of the strong hooks of their feet as do the Gammari. The young remain for a con- siderable time attached to the female parent, nestling in the ovigerous pouch or rambling over her body. Their interior structure, as observed by Treviranus and Roussel de Vauzeme, closely approaches that of the Isopoda, the nervous system consisting of eight bilobed ganglions exclusive of the supra-cesophageal, each segment of the body being provided with a ganglion. CYAMUS. 81 These creatures crawl but slowly, digging the hooks of their feet into the skin of the whale to the base of the claws, whence it is difficult to detach them by force, without cutting through the epidermis, when they are freed ; it is also dangerous to attempt their removal, as their strong claws easily penetrate the fingers, and cause considerable pain. Their branchiae are brought together on the back, and directed forwards, except in E. gracilis. which carries them in the opposite direction. When de- tached, and placed in sea-water, they are unable to swim, neither their branchiae nor limbs enabling them to perform such an operation. When a whale is hoisted on board-ship, the Cyami attached to it extend their branchiae, agitate their antennas and hooked legs, as if desirous to seize something else. If the branchiae are cut, the animals do not appear to be affected, but when the antennae are similarly treated, the animals move about irregularly, from side to side and backwards, as if drunk. When injured, the branchiae are never renewed ; but if the legs are broken off at the base, new limbs are produced ; but this is not the case if only a portion of the leg be injured : hence it is not unusual to meet with Cyami having one or more legs of smaller size than the rest. M. Roussel did not observe any species of Cyamus on the dolphin, cachalot, or " baleine a ailerons." He states that it is generally believed by the fishermen that the alba- trosses, which abound about the fishing stations, pick the Cyami off the bodies of the whales, but he had never found any of these Crustacea in the stomachs of such specimens of these birds as he had dissected. The structure of the mouth and intestinal canal of the Cyamus sufficiently prove it to be a gnawing, and not a suctorial, animal. Indeed, on opening its alimentary VOL. II. G 82 CYAMID^E. canal small portions of the skin of the whale are found in it, and on removing the Cyamus from the whale, the epidermis, whence it is taken, is found to have been gnawed off. The eggs of the Cyami are spherical, agglomerated, and of a yellowish-white colour : they are deposited in the ventral pouch, which is formed of thin mem- branous plates, ciliated along the margin, and here the young are hatched and carried until they are fully developed. Whilst the eggs remain in the incubatory pouch, the female detaches herself from her companions, rejoining them when she had got rid of her young brood. The young ones are complete in all their parts ; the head, however, is proportionally of an enlarged size, the bran- chiae globular, the anterior pair of legs not much smaller than the following, and the antennae short. There ap- pears, according to M. Roussel de Vauzeme, considerable difference in the treatment of the young brood by their parents. The females of C. ovalis arrange themselves side by side on the tubercles of the head of the whale, covering their young with their bodies, which form strong shields for their protection. In C. gracilis, on the contrary, the females and males, as well as young, are mixed together, whilst the young of C. erraticus are found isolated and fixed on the different parts of the body where they had been left by their parents ; but in ac- cordance with their future mode of life, M. Roussel gives a curious instance of the effect of the distinction of habits in the different species of this genus : in answer to an inquiry by Messrs. Audouin and Milne Edwards, as to whether Cyamis gracilis might not be the young state of C. ovalis, M. Roussel relied on the different habits and colour, as well as the particular form of the CYAMUS. 83 body, whilst out of several hundred Cyami preserved in the collections at the Jardin des Plants he was only able to detect a single individual of C. erraticus, the mode of life of that species not rendering it so apparent to the collector as the species which associate together in vast numbers on prominent parts of the body. From the further observations, both of Martens and Roussel de Vauzeme, it would appear that the violent storms of the winter season are very destructive to the Cyami, many of the parts of the whales generally in- fested by them being then free ; those which survive being feeble and discoloured. He only observed C. er- raticus to preserve its rosy tint, but its numbers were also diminished. The relations of the Cyami with other Edriophthalmous Crustacea are very interesting. Placed by Linnaeus, Pallas, and Miiller amongst the Onisci, and arranged by Fabricius with the Aselli and Cymothoe, their relationship with the order Isopoda was indicated ; and M. Roussel de Vauzeme, the author of an elaborate memoir on the genus in the " Ann ales des Sciences Naturelles" (2e Ser. vol. i.), maintained their nearer approach to the Isopods than to any other Crustacea. Latreille, at first, placed the genus with the Gammari, in the order Amphipoda, but he subsequently united it with Caprella, to form the distinct order Lcemodipoda ; nor can we doubt (notwith- standing the objection of M. Roussel, founded on the variations in the mode of insertion of what he terms the fore legs) that this is the legitimate position of the genus ; in fact, Caprella is but a laterally compressed Cyamus, and but little imagination is required to con- vert the former into an excessively attenuated Cyamus, so perfectly similar is the disposition of the segments of the body and limbs in both animals. G 2 84 CYAMID.E. Savigny (as Fabricius had, indeed, previously done) pointed out a supposed affinity of Cyamus with Pycno- gonum ; and Strauss, having their parasitic habits in view, proposed to unite them with Nymphon, Cecrops, Pycno- gonum, Dichelestion, &c., into a most heterogeneous group under the name of Crustacea Parasita. CAPTURE OF A WHALE. AMPHIPODA. ABERRANT!^. C YAM US CETI, 85 CYAMIDJ1. CYAMUS CETI. The Whale Louse. Specific character. Body depressed, elliptical, segments gaping at the sides (male narrower?). Third and fourth segments of the body with one long brauchia on each side ; armed at the base with two short appendages ; second pair of hands armed beneath with two obtuse teeth, between which is a lunate incision. Length nearly half an inch. Pediculus Ceti. MARTENS, Voy. Spitzbergen, viii. tab. ix. fD(167l). LINN.EUS, Fauna Suecica, p. 499, No. 2056 (0ms- cus C.). Syst. Nat. ii. p. 1060. SEBA, Thesaurus, t. i. pi. xc. fig. 5. PALLAS, Spicilegia Zool. fasc. 9, pi. iv. fig. 14, A B c. DE GEER, Mem. t. vii. pi. xlii. figs. 6, 7 (Squille de la Baleine). FABRICIUS, Ent. Syst. Suppl. p. 570 (Pycnogonum C.}. LAMARCK, Syst. Ann. s. Vertebr. p. 166 (Cyamus C.). MULLER, Zool. Dan. iii. pi. cxix. figs. 13-17 86 CYAMID/E. Bosc. Hist. Crust, ii. pi. xvi. fig. 2. SAVIGNT, Mem. i, pi. v. LATREILLE, Hist. n. Crust. &c. vi. p. 331, pi. lii. fig. 4. Genera Ins. t. i. pp. 60, 176. DESMAREST, Cons. Crust, p. 280, pi. xlvi. fig. 4. WHITE, Pop. Hist. Brit. Crust, p. 219, pi. xi. fig. 6. Cat. Brit. Crust, p. 62. SPENCE BATE, Cat. Amph. Brit. Mus. p. 366, pi. Iviii. fig. 2. Ann. Nat. Hist. Feb. 7, 1857. LEACH, Edinb. Enc. vii. p. 404 (Panope Ceti). Trans. Linn. Soc. xi. p. 364 (Larunda C.). Suppl. Enc. Brit. i. p. 426, pi. xxi. SAMOUELLE, Ent. Comp. p. 106. M. EDWARDS, Hist. d. Crust, iii. p. 113. TREVIRANUS Verm. Schrift, ii. p. 1. Die Wallfiscblaus, pi. i. Cyamus erraticus. ROUSSEL DE VAUZEME, Ann. Sc. Nat. 2nd Ser. t. i. p. 259, pi. viii. fig. 22, 23. MILNE EDWARDS, Hist. N. Crust, iii. p. 113. GOSSE, Mar. Zool. i. p. 131 (not of Spence Bate, Cat. Amph. Brit. Mus. p. 368). ALTHOUGH the early descriptions of the whale louse, of which, until recently, it was supposed that there was but a single species, are vague, the figures and locality suffi- ciently indicate that the creature, so beautifully figured by Savigny, in the first volume of his " Memoires," and which is identical with the one represented in the above woodcut, was the species intended by Linnasus, De Geer, &c., the early representations of which exhibit only a single linear appendage attached on each side of the third and fourth segments of the body. We presume likewise, and are confirmed herein by M. Milne Edwards, that the C. erraticus of M. Roussel de Vauzeme is intended for the same species ; his figure probably, from its narrower size, representing a male. The fact of several distinct species having been found to infest the whale, was doubtless the reason which induced the last-named observer to sink the specific name Ceti as of generic extent ; but this principle is at variance with the rules of the best zoological no- menclaturists. By some oversight, Mr. Spence Bate, in his work on the Amphipoda (pp. 366, 368), has given C. ceti and erraticus as distinct species, referring, under CYAMUS CETI. 87 the former, to M. Milne Edwards, who, however, rejects the Linnean specific name Ceti. The animal represented by the former (Plate 58, fig. 2) from Talcahuna, in the Paris Museum, appears to be a male, being much more slender than the specimens represented by Savigny, and in our woodcut. The head is oval, its hinder portion being connate with the first segment of the body, of which the central portion is much shortened, the sides swelling into rounded lobes. The upper antennae (b) are about twice the length of the head ; the first, second, and third joints of nearly equal length ; the first being the thickest and somewhat triquetrous, the terminal joint is minute and conical. The lower antennae (c) are very minute and slender, not being more than one-third of the length of the basal joint of the superior, with four joints, the third being the longest, and the fourth very minute. The upper lip (*), copied from Savigny, is rounded at the base and slightly emarginate in the middle of its fore margin, whilst the tongue (#*) is somewhat four-lobed, or rather it is deeply incised in the middle of its fore margin, and is furnished in the centre with a narrow bipartite projection, shorter than the lateral lobes. The mandibles (d) are somewhat triangular, destitute of a palpiform appendage, but furnished with a separate denticulated tooth below the extremity, which is similar in character : the first and second maxillae are affixed on the same plane (as in the Myriapoda, although not sol- dered into one piece as in that order) : the first pair (e) are large and flattened, apparently three-jointed and des- titute of palpi, the terminal joint being large, rounded at the outside of its extremity, with several hairs forming a brush in the middle of the convex side ; the second pair of maxillae (/) are minute, and apparently three-jointed, the second and third joints being very minute ; they are 88 CYAMID.E. affixed upon a common, elongated basal piece, inserted betwen the basal joints of the first pair, and the mouth is closed below by a transverse piece (fig. #), emarginate in it§ fore margin, which Savigny terms a " levre auxiliare sans lobes," but. which we regard as the ventral surface of the segment that carries the pair of foot -jaws (which are attached at its sides); these are five-jointed, the fourth being the largest. The first segment of the body is small, with the front part rounded on its upper edge, its lower being dilated in the middle into an angle. The second segment is much longer than either of the two following, its fore margin is nearly straight, having a very minute rounded prominence towards each of its lateral anterior angles ; it is deeply channeled across its centre. The legs attached to this segment are very large and broad, the second joint strongly angulated on its upper edge, the small third joint rounded and prominent on its lower edge, and the fourth joint with a moderate semi-lunate impression on its lower edge. The third and fourth segments of the body are very short, the fourth having its sides produced at the posterior lateral angles, whilst its hinder margin is emarginate on each side. The fifth, sixth, and seventh segments are each as long as the second, but gradually narrowed, their fore and hind margins are sinuated, leaving spaces be- tween the joints. The legs attached to these three seg- ments are nearly uniform in size, large and broad, with the fourth joint somewhat conical, having the upper edge rounded ; the terminal joint in all the legs is very acute, curved, and as long as the preceding joint, thus giving the animal strong powers of prehension. The tail is very minute and rudimental. The full-grown female has the body wider than the male, and has the third and CYAMUS cm. 89 fourth segments furnished with large foliaceous plates, forming an incubatory sac. We have no precise details of the locality and notice of capture of this species beyond the general statement of its being found on the whale in the British seas. British specimens exist, however, in the British Museum, as well as in the Hopeian, Stephensian and Westwoodian collections, now in the Oxford Museum, &c. On some of the females which we have examined, we have found the young fixed firmly to different parts of the body, about one-twelfth of an inch long, distin- guished from their parents by the proportionally larger size of the head (with which the following segment is confluent), the shorter antennae, and especially by the size of the first pairs of legs, which are equal to the following, all being small, and much less strongly dilated than in the adult state, and also by the small rudimental size of the branchiae. M. Roussel de Vauzeme informs us that the species of Cyamus to which he gives the name of C. erraticus, and which we have regarded as the true Linnean C. ceti, differs considerably in its habits from the other species of the genus which he had observed. The former species attaches itself at the base of the tubercles of the different parts of the head, fixed upon the smooth skin in the inter- vals between them, and but rarely mingling with Cyamus ovalis. They, however, wander about over different parts of the body, or hide themselves in the folds of the eye- brows, the commissure of the lips, navel, genital and anal parts. They also especially attach themselves to wounded parts of the body, and on one occasion M. Roussel found a whale injured by the swordfish, the suppurating wound of which had attracted a vast number of individuals of this species. The structure of the 90 CYAMID,E. body and limbs of this species, indeed, are eminently fitted for its wandering mode of life ; its more slender body, with longer hooks to the claw-legs, enabling it to withstand the shock of the waves on the naked parts of the body of the whale, whereas the structure of the legs of C. gracilis compel it to a sedentary mode of life. CYAMUS CETJ, YOUNG. CYAMUS OVALIS. 91 A MPHJP ODA . ASER11ANTIA. CYAMUS OVALTS. Specific character. Body depressed, elliptic-ovate, with the segments not gaping apart at the sides. Third and fourth segments of body, with two pairs of branchiae on each side, of unequal length ; those of the third segment having at the base only a short slender appendage, those of the fourth seg- ment having two appendages of unequal size at the base. Hand of the second pair of legs with two obtuse teeth. Length about half an inch. CyarmiS omlis. ROUSSEL DE VAUZEME. Ann. Sci. Nat. 2nd ser. vol. i. p. 259, pi. 8, hg. 1-21. MILNE EDWARDS, Hist. N. Crust, iii. p. 113. Ann. Sci. Nat. 2nd ser. iii. pi. 14, fig. 13, 14. Regne An. ed. Crochard Crust, pi. 63, fig. 3. GUERIN, Icon. R. An. Crust, pi. xxviii. fig. 4. WHITE, Pop. Hist. Brit. Crust, p. 219. Cat. Brit. Crust., p. 62. GOSSE, Marine Zool. i. p. 31. SPENCE BATE, Cat. Amph. Brit. Mus. p. 367, pi. Iviii. fig. 3. Ann. Nat. Hist. (Feb. 1857), 2nd ser. xix. p. 152. THIS species is indicated as British by Mr. Adam White in his " Catalogue of the British Crustacea," but we have seen no specimen which we are able to identify with M. Roussel de Vauzeme's figures, which we have consequently been under the necessity of copying in the accompanying woodcut.* This species is at once distin- guished from C. ceti by its elliptic-ovate form, by the * The figure on the right hand represents the male, seen on its ventral surface, whilst the left-hand figure represents the under surface of the body of the female, showing the incubatory pouch. 92 segments being not wide apart at the lateral margins, and by the possession of two slender filiform branchiae at- tached to each side of the third and fourth segments of the body. The species represented by Mr. Spence Bate (Plate 58, fig. 3) is from the Cape of Good Hope, and possesses a very strong tooth near the extremity of the fourth joint of the second pair of legs. We presume, notwithstanding its locality, that it is identical with M. Roussel de Vauzeme's species. The branchial ap- pendages of the males are longer than those of the females. In the species before us the anterior pair are furnished at the base with a single pointed appendage, whilst the posterior pair have this appendage doubled, its branches being rather unequal in size ; these appendages exist in the female in the modified form of large flat- tened plates, or valves, extending beneath the middle of the body. These plates are concave, pedunculated, fringed at the edges, and formed of a double transparent membrane : thus constituting a sac without an external orifice. These plates, lying upon each other, serve as a pouch, within which the eggs are deposited, and the young hatched. Some uncertainty has been entertained as to the real nature of the branchial appendages, which have been regarded as simple stems, false legs, pseudo- branchiae, vesicles without determinate use, and organs of respiration ; but the direct observation of M. Roussel on the living animals has demonstrated that they are branchial canals in communication with the dorsal vessel, and of a membranous texture, whilst the appendages at their bases in the male are differently organized, being crustaceous, and unfitted for organs of respiration ; and the plates of the ovigerous pouch in the female are also destitute of branchial canals, and consequently unable to perform the functions of gills. CYAMUS OVALIS. 93 According, also, to M. Roussel de Vauzeme, Cyamus ovalis, as well as C. yracilis, are only found upon the tu- bercles of the chin, lips, and upper jaw of the whale, and especially upon the larger tubercle of the head, which the whale-fishers call the crown, near the blow-holes, and the horny excrescences with which it is surrounded. Sometimes, indeed, C. ovalis is found in such vast num- bers in this last situation, that at a considerable distance the patch of white colour, produced by their presence, may be observed when the whale comes to the surface to breathe. In this situation the individuals of C. ovalis arrange themselves with considerable regularity, by which they are distinguished from C. gracilis, which are scattered about more irregularly. The young of C. ovalis, as figured by M. Guerin Meneville, in the " Iconographie du Regne Animal/' is more regularly elongate-ovate than the young of C. ceti, as figured above by ourselves, with the legs almost cylin- drical, the fourth joint but moderately dilated ; indeed, according to M. Milne Edwards (Ann. Sci. Nat. vol. iii. p. 329), "Les jeunes Cyamus ont une forme suelte et elancee," all the segments being perfectly alike, re- sembling portions of a cylinder with the legs " gr61es, cylindriques, et parfaitement extensibles ;" and with the branchial vesicles not more developed than in Proto, Caprella, &c. 94 OYAMID.E. AMPH1PODA. ABERRANTIA. CYAMIDtf. CYAMUS GRACILIS. Specific character. Body small, oblong ; segments of the body emarginate at their lateral margins. Third and fourth segments of the body with a pedunculated branchia on each side, each furnished at its base with two very short appendages. Second pair of hands with the palm slightly concave. Length \ inch. Cyamus yracilis. ROUSSEL DE VAUZEME, Ann. Sci. Nat. 2nd ser. vol. i. p. 243, pi. 8, fig. 24, 25. MILNE EDWARDS, Hist. N. Crust, iii. p. 113. SPENCE BATE, Cat. Amph. Brit. Mus. p. 366, pi. Iviii. fig. 1. GOSSE, Mar. Zool. i. p. 131. WHITE, Pop. Hist. Brit. Crust, p. 219. OUR figures of this species represent, firstly (the cen- tral figure), the animal as drawn of the natural size by M. Roussel de Vauzeme ; secondly (the right-hand figure), a copy of Mr. Spence Bate's figure (PI. 58, fig. 1), drawn from individuals in the Paris Museum, found at the Cape of Good Hope, and also taken during the voyage of the Chevrotte, but without any indication of locality ; and thirdly (the left hand-figure), an animal in the British Museum, to which the same name has been applied, and which is stated by Mr. Adam White to inhabit the British seas ; it is evidently an individual in an immature state, having minute antennae, and the CYAMUS GRACILIS. 95 first pair of legs of moderately large size, although smaller than the following limbs. The species, according to M. Roussel de Vauzeme, has the body small and oblong, with a single branchia attached to each side of the third and fourth segments, each branchia having two very short appendages at its base, and the second pair of legs have the large penultimate joint with a slight concave impres- sion on their under surface. We regret that our igno- rance of the precise locality of the supposed British specimen above mentioned, and its immature condition, as well as the very concise notice of this species by M. Roussel himself, prevent us from giving a satisfactory account of it. The only notice of its habits, as distinct from those of C. ovalis, has been already detailed by us in our account of the last-named species. 96 AMPH1PODA. ABERRANT! A. CYAM1D.E. CYAMIDM* CYAMUS THOMPSONI. Specific character. Head triangular ; antennae very short ; two middle segments of body narrower than the preceding and following. First and second pairs of legs equal in size, and not larger than the posterior pairs. Third and fourth segments with a single very short oval branchia on each side. Length about one-sixth of an inch. Cyainus Tkompsoni. GOSSE, Mar. Zool. i. p. 131. Ann. Nat. Hist. xvi. p. 30, pi. iii. fig. 11 (1855). WHITE, Pop. Hist. Crust, p. 219, fig. 225. Cyamus Thomsoni. SPENCE BATE, Cat. Amph. Brit. Mus. p. 368, pi. Iviii. fig. 5. Ann. Nat. 2nd ser. xx. p. 525 (Jan. 1858). Cyamus Delphinii. GU£RIN M^NEVILLE, Iconogr. E. An. Crust, texte p. 25, pi. xxviii. fig. 5 (adult state ?) Cyamus gracilis. SPENCE BATE, Ann. Nat. Hist. 2nd ser. xix. p. 152 (Feb. 1857). THE animal which forms the type of Mr. Gosse's species is fortunately preserved in the British Museum collection, and has served us for the accompanying figure. It is evidently in an immature state, as shown by the small size of the antennae, the uniform size of the legs, and the rudimental condition of the branchiae ; the legs, however, are considerably stronger than in the young CYAMUS THOMPSONI. 97 of C. ceti, which we have represented in our figures in page 90 ; and in all, the penultimate joint is large and angulated in the middle of its lower edge. The specimen was obtained by Mr. William Thomp- son, of Wey mouth, attached to an individual of Hy- peroodon bidens captured in Portland Roads in 1854. This is the species referred to by Mr. Spence Bate in the " Annals of Natural History," for February, 1857, 2nd Series, under the name " C. ?C. gracilis. Gosse," as stated by Mr. Bate himself in the same work, 2nd Series, vol. xx. p. 525, where it is referred to C. Thomsoni [Thompsoni]. Gosse, "Ann. Nat. Hist.," vol. xviii. [xvi.] 1855. In our introductory observations on the genus, we have seen that M. Roussel de Vauzeme had not observed any species of this genus on any of the dolphins ; but the capture of this specimen by Mr. Gosse disproves such a statement, whilst M. Gu6rin Meneville, in his " Iconographie du Regne Animal,"* has described and figured a species under the name of C. delphinii, taken upon the generative organs of the dolphin on the coast of the Antilles. It is of an oval-elongated form, with the segments of the body touching each other at the sides except the terminal ones, which are a little gaping. The great joint of the second legs bears a strong tooth on its under edge, the branchial filaments (one on each side of the third and fourth segments) are very short, and much shorter than the legs. The basal articulations of the hind legs are strongly dentated and various in form. Mr. Spence Bate (Cat. Amph. p. 366) considers this species to be only a variety of C. gracilis. It has, how- ever, to be determined whether the animal is uniform in its residence on the dolphin, or only exceptional, as * Crust, texte, p. 25. VOL. II. H 98 CYAMIDaE. appears probable from the absence of specimens ; if the former be the case we should not hesitate to regard it as a distinct species, of which the precise characters have to be detailed. How far, also, it is identical with Mr. Gosse's animal must be left for future determination, when the immature states of C. delphinii shall have been ascertained. CYAMUS DELPHINII, Q. M., MALE AND FEMALE. ISOPODA. 99 Order— ISOPODA. THIS order of Crustacea was first defined by Latreille, and was named Isopoda, in contradistinction to the Am- phipoda, from the Greek words i