B & fj. e SIDNEY I. SMITH, New Haven, Conn. A HISTORY OF THE BRITISH SESSILE-EYED CEUSTACEA. BY C. SPENCE BATE, F.E.S., F.L.S., ETC., AND J. 0. WESTWOOD, M.A., F.L.S., HOPE PROFESSOR OP ZOOLOGY IN THE UNIVERSITY OF OXFORD, ETC. IN TWO VOLUMES.— VOL. II. LONDON: JOHN VAN VOORST, PATERNOSTER ROW. M.DCCC.LXVIII. LONDON I PRINTED BY WOODFALL AND KINDER, MIT/FORD LANE, STRAND, W.C. ' 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 antennse 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, BrachysceluSy &c., the fifth and sixth segments are incorporated into one. The appendages are more liable to aberration than in the Gammaridce. 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. v B , . 2 HYPERINA. 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 Earn. I.— HYPERIIDjE. 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. LESTRTGONUS. 3 A MP BIPOD A . II YPERIID^E. Ul'PERINA. 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 HYPERIIDJ2. 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 raini 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. UYPERllDsE. LESTRIGONUS EXULANS. Specific character. Antennse 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. Lestriyonus cxulans. KROYER, Gronl. Amfip. p. 68, pi. iv. f. 18, a, &, c. EDWARDS, Hist, des Crust, t. iii. p. 82. SPENCE BATE, Cat. Arnph. 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 HYPERIID.E. 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 antennae 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 HYPERIIM. AMP HIP 01) A. HYPERINA. HYPERIID^E. LESTRIGONUS KINAHANI. Specific character. Antennae subequal ; the superior being rather the longer, equally the entire length of the animal. Length ^ inch. Lestrigonus 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 antennae, we believe that the most acute observation would not be able to detect any distinguishing feature. The antennas 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. LESTUIGONUS KIN All ANT. 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 UYPERIID.E. AMPHIPODA. HYPERIID^. HYP ERIN A. Genus— HYPERIA. (Latreilk.) 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. Mus. 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. Antennae 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 antennas 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 Krb'yer 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 antennse) 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 Lestrigonus and Hyperia, from the same locality, and we found that all the adult Hyperia of which the sex could be detected were females, but that none of the Lestrigoni were of that sex. 12 HYPERIIJXE. AMPHIPODA. HYPERIN4. HYPERIID2E. c HYPERIA GALBA. Specific character. Cephalon large ; pereion distended ; pleon compressed. Antenna? 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. Hyperia Latreittii. 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. 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. HYPER1A GALBA. 13 GrtiERiN, Icon. R. An. Crust. \>\. 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. Metocchus medusarum, WHITE, Hist. Brit. Crust, p. 207. Hiella Orliynii. 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 Rhizostoma 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 r This mark is intended to symbolize the young animal. IIYPERIA 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 obtuse 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. ,' v\ 16 AMPHIPODA. ETFERINA. HYPERITP.E. HYPERIID^E. HYPERTA OBLIVIA. Specific character. Superior antennae as long as the depth of the cephalon; Inferior antennas 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 £ inch. Hypcria ollirta. KK.OYER, 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. Aniph. 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 IIYPERLY OBL1VTA. 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 HYPERinXE. 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 confervae, but we have not seen a specimen. * Typliis nolens. WHITE, Cat. Crust. Brit. Mus. p. 78. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Rep. Brit. Assoc. 1860, p. 225. Anonyx (?) nolens. WHITE, Pop. Hist. Brit. Crust, p. 169. 20 PHRONTMlIXffi. Fam. II.— PHRONIMID.E. INFERIOR antennas 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. PH RON IMA. 21 A MPH1P 0 DA . PUR ONI M IDES. HYPER1NA. Genus— PHRONIMA. Pkronitna. LATREILLE, Hist. Nat. Crust, et lus. vi, p. 289. SPENCE BATE, Cat. Ainph. 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 antennae 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 flag ell um, 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 PHRONIMHXE. 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. AMP If I POD A. HYPERINA. PHRON1MIDES. PHRONIMASEDENTARIA. Specific character . Cheliforin 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 (Gammarellus) sedentarius. HERBST. Naturg. der Krabben, £c., ii. pi. xxxvi. fig. 8. Phronima scdentaria. \ 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.)pl. Iviii. fig. 3. PHRONIMHXE. GUEKIN MEN., Icon. E. 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 antennas are short, and 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 SEDENTAUIA. 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 jointless; 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 Bmchi/scehis cruscalam as described by Spence Bate, "Anii;tls 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 PHRON1MID2E. 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 Gaimardii, 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 Phronimce 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 ber of young Phronimce, in company with their parent. In the British Museum is a specimen of Doliolum papil- loswn, 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 ABERRANTJA. Group— ABEBBANTIA. 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 Dulichiidae of Dana. Fam. I.— DULICHIIDjE. 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- DULICHIID2E. 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 ULWHIID^E, Genus— DULICHIA (Kroyer). DuUchia. KROYER, Nat. Tidsk. n.s. i. p. 521. Voy. en Scand. pi. xxiii. fig. 1. S PENCE BATE, Ann. Nat. Hist. xx. p. 526. Dyopedos. SPENCE BATE, Ann. Nat. Hist. 2 ser. xix. p. 150. Generic character. Superior antennae longer than the in- ferior. Inferior antennae inserted posteriorly to the superior. Gnathopoda chelate. Pereiopoda sub equal, having neither the coxse 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 antennas 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. DULTCTTIA PORRECT\. 31 AMPHIPODA. ABERRAXTH. DULICHIA PORIIECTA. Specific character. Cephalon not produced into a rostrum. Pereion and pleon dorsally smooth. Eyes round, not elevated upon a tubercle. Superior antenna? 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. Dulicliia 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 DULICHIIIXE. 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 palm 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 antennas, the small sizes of the hands, and the shortness of the last pair of legs. DULICHIA FALCATA. AMPHIPODA. ABERRANTIA. 33 DULICHIID^E. DULICHIA FALCATA. Specific character. Cephalou without a rostrum. Body smooth. Superior antennre about two -thirds the length of the animal. Second pair of gnatho- poda having the propodos armed beneath with a crooked tooth near the base, and a sharp curved tooth near the distal extremity. Length, \ inch. liia falrata. SPENCE 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 antennas 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. 11, D 3 i 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. CAPRELLID7E. 35 Fam. II.— CAPRELLID^. 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 CAFRELLID.E. A MPHIPODA . CA PRELUDE. ABEREANTIA. Genus— PROTO. 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 EDWARDS, Hist, des 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.-)- He has evidently, also, fallen into error in giving the Gammarus pedatus of Montagu and of Miiller and the Squilla ventricosa of Muller as three distinct species, referable to separate sections or sub- genera. * Eegne 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}. t 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 imirticulated flagellum of the antennae and want of the four hind legs. It is possible that these may lie subsequently developed '( 38 AMPH1PODA. ABERRANT1A. CA.PRELLIDJE. CAPRELLID^E. PROTO FED AT A. Specific character. Superior antennae nearly half the length of the animal. Inferior antennse about half the length of the superior. First pair of gnathopoda having the propodos triangular, palm oblique, armed with small spines, and defined 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 denned by a process, armed with a strong spine. Length g inch. Gammarus pedatus. ABILDGAARD in MULLER, Zool. Dan pt. iii. p. 33, pi. ci. figs. 1, 2. Cancer (Gammarus) pedatus. MONTAGU, Trans. Linn. Soc. xi. p. 6, pi. ii. fig. 6. Proto pedata. 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 pedal urn. DESMAREST, Consid. sur Crust, p. 27(3. Leptomera pedata. GOSSE, Mar. Zool. p. 131. fig. 224. Leptomera pedata. LATREILLE, Regne An. iii. p. 51. GUERIN, Iconogr. Crust, pi. xxviii. fig. 3. MILNE EDWARDS, Hist, cles 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. ^'[idlla 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 antennae are about half the length of the animal ; the ilagellum 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 lumelke large and elliptical (to which the figures of Miiller 40 CAPRELLTDJ3. 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. It 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 lamellae smaller and cylindrical (to which all the Berwick specimens are referable). PHOTO 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 CAPllELLID.E. A MPHIP ODA . CA PRELLIDJE. ABERRANTIA. PROTO GOODSIEII. Goodsir's Spectre Shrimp. Specific character. Superior antennae about one-tliird 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 Goodsirii. 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 nagellum 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, denned 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 GOODSI1UI. 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 CAPRELLILLE. ,1 MPHIP ODA . CA PRELUDE. ABERRANTIA. Genus— PROTELLA. Protella. DANA, U. S. Explor. Exped. p. 812. SPENCE BATE, Cat. Ampb. 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- pretta, 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. IMJOTKLLV PIT ASM \. 45 AMPHIPODA. ABERRANT1A. CAPRELLID&. PROTELLA PHASMA. Montagu's Skeleton Shrimp. Specific character. Ceplialon, 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, ami one near the posterior margin. Length rather more than half an inch. Cancer phasma. Caprella pliasma. Caprella pliasma. JEyina longispina. Prof el l« 1miti'i*i>hi<:. MONTAGU, Trans. Linn. Soc. vii. p. 66, pi. vi. fig. 3. 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. Journ. viii. p. 297. JOHNSTON in Lou- don's Mag. Nat. Hist. viii. p. 6G9. RATIIKE, 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. 5. p. 476, 1844-6. SPENCE BATE, Ann. Nat. Hisi. '_! ser. xix. p. ir.l. 46 CAPRELLID^E. Caprella spinosa. GOODSIR, Edin. Phil. Journ. xxxiii. pi. 3, f. 1-3. WHITE, Pop. Hist. Brit. Crus. p. 197. Protdla phasma. SPENCE BATE, Cat. Amph. Brit. Mus. p. 351, pi. Iv. fig. 4. A stacus phasma. 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 CAPRELLID/E. Couch among confervas, at Lariggan Rocks, Mount's Bay, Cornwall. In Norway it has been recorded by Rathke, and Kroyer has procured it at Christiana in S vveden. 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 : — O V " Methought 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 A MPHIP ODA . CA PRELLID&. AUEItRANTIA, Genus— CAPRELLA. Capretta LAMARCK, Hist, des Anira. sans Vert. p. 165. LEACH, Linn. Trans, xi. p. 363. MILNE EDWARDS, Hist, des Crust, iii. p. 105. KROYER, Nat. Tidssk. iv. p. 496. .JEgina. 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 CAPKELLID.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 clerable 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 JEyina. 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. 52 AMPHIPODA. ABERRANTIA. CAPRELLTD.E. CAPRELLIDjE. CAPRELLA LINEAR1S. 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 denned by a short process armed with a spine. Length | inch. Cancer linear is. Caprella linearis. LINN^US, Syst. Nat. ii. p. 1056 ? Herbst. Krabben, ii. pi. xxxvi. fig. 9, 10. MILNE EDWARDS, Hist, des Crust, iii. p. 106. DESHAREST, 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. GOODSIR, 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. CAPKELLA LI NBA HIS. 53 Cancer (Antaeus) atomos? PENNANT, Brit. Zool. ed. 1777, iv. p. 17, pi. xii. fig. 32. BASTER, Opusc. Subs. pi. iv. fig. 2. Cancer (Astacus) punctata. Risso, Crust, de Nice, p. 130. Hist. Nat. Eur. merid. v. 102. Oiiiscus scolopendroides. PALLAS, Spic. Zool. ix. p. 78, pi. iv. fig. 15. SquiUa quadrilobata ? 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 CAPRELLID.I:. 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 LINE A HIS. 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 CAPRELLID.E. 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 LOB AT A. 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 Gronl. 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. 3. Ann. Nat. Hist. 2 ser. xix. p. 151. Squilla quadrilobata. MULLER, Zool. Dan. t. 114, fig. 11, 12. jEyina longicornis. KROYER, Voy. en Scand. pi. xxvi. fig. 3. Caprella Icevis. GOODSIR, Edin. New Phil. Journ. xxxiii. p. 189, pi. iii. fig. 4. WHITE, Pop. Hist. Brit. Crust, p. 215. Hist. Brit. Crust, p. 60. Caprella linearis. 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.L. 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 bodv O O •> 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, find will probably be found to exist all round the CAPEELLA LOBATA. 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. ^iiiiiiiiki* . 8 * '' 60 CAPRELLUXE. AMPHIPODA. ABERRANTIA. CAPRELLID^E. CAPRELLA ACUTIFRONS. Specific character. Ceplialon 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 defined by an obtuse angle armed with a spine ; limbs very robust. Length 57g inch. Caprella acutifrons. Cancer (Astacus) atomos? Caprella Penantis. Caprella Pennantii. 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.bis 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. Kist. 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 CAPRELLA ACUTIFUONS. C)l 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 flagellurn 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. (UPKELL/V HYSTHIX. AMPI1IPODA. ABERRANTLY (53 CA PRELUDE. CAPRELLA HYSTHIX. Specific character. Tuberculated along the dorsal surface, the tubercles increasing posteriorly. Second pair of gmitliopoda having the propodos ovate ; palm convex, defined by a blunt process surmounted by a spine. Length | inch. CapreUa Hystrix. CapreUa acumin if era . KROYER Nat. Hist. Tidssk. iv. 603. pi. viii. fig. 20-26. Voy. en Scaud. 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 denned 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 C. 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. hystrioc). 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. 65 AM PHI POD A. ABERRANT^. CAPRELLIDM. 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 585 of an inch in the male, and 575 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 acantliifera. Caprella, calva. VOL. II. F 66 CAPRELLIM. Caprella acununifem. LATREILLE, in Nouv. Diet. d'Hist. Nat. 2nd Edit. vi. p. 433. DESMAREST, Consid. Crust, p. 277 (not of Johnston). S PENCE 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 ACANTIUFEKA. (>7 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. * Iu 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 f 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/era. Both these names have been misapplied by Johnston and R. Q. Couch to the cornuted females of the following species. F 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 | 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. Ainph. 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 antennas 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 CAPRELLLD^. 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 (acuminifera), which also may possibly be but a variety of this same species. CAPRELLA ^QUILIBRA. AMPHIPODA. 71 CA PRELLIDJE. CAPRELLA yEQUILIBRA. 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. Caprella equilibra. Caprella Januarii. SPENCE BATE, Cat. Amph. Crust. Brit. Mus. p. 362, pi. Ivii. fig. 5. SAY, Journ. Acad. Philad. i. p. 391. 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.E. 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 antennas 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 ^EQUILIBRA. 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 Gorgonicr, so common in the salt-water creeks of the southern coast. 74 CAPRELL1DJS. A MPHIP ODA . CA PRELUDE. 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.'5 Caprella spinulata. R. Q. COUCH, in Report Penzance Nat. Hist. Soe. 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 confervas, 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. AMPHIPODA. AHERKANTIA. 70 CAPRELLI.DJ?. 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. Antennas moderately long and slender ; hind legs slender, with the hand simple. Length \ inch. Podalirius typicus. KROYER, Nat. Tidssk. 2nd Ser. i. p. 283. Yoy. en Scand. pi. xxv. fig. 1 a — I. 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 CAPRELLID.E. 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. c YAM I D.I:. 77 Fam. III.— CYAMID.E. 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 antennae 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 CYAMIDJE. 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 -join ted 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. C ' 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 CYAMID.E. 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 CYAMID.E. A MPH1P ODA . ABERRANTIA. Genus— CYAMUS. Cyamus. LAMARCK, Syst. d. Anira. 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. SAHOUELLE, Ent. 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. C YAM US. 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 antennae 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 8.2 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. Houssel 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 yracilis 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. 80 body, whilst out of several hundred Cyami preserved in the collections at the Jarclin 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 Muller 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 " Annales 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 Lamodipoda ; 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 CYAMIDJS. 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. (YAM US CRT I. 85 AMPHIPODA. ABEREANTLI. GYAMIDJE. d 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 branchia on each side ; armed «it 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. Pediculu.s Ceti. MARTENS, Voy. Spitzbergen, viii. tab. ix. f D (1671). LINN^US, Fauna Suecica, p. 499, No. 2056 (Oms- 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 £aleine). FABRICITTS, Ent. Syst. Suppl. p. 570 (Pycnoyonum C.}. LAMAKCK, Syst. Ann. s. Vertebr. p. 166 (Cyamus C.). MULLER, Zool. Dan. iii. pi. cxix. figs. 13-17 86 CYAMIDJE. 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. DESAIAREST, 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. Arnph. 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. Cornp. p. 106. M. EDWARDS, Hist, d. Crust, iii. p. 113. TREVIRANUS Verm. Schrift, ii. p. 1. Die "VVallnschlaus, 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 Linnaeus, 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, 068), 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 ( ~ ^ O £ -I-2 l-i-H rH o ^ Jj rH &r^ r-3 . cS .rC 2 "S -a rH -(J 1-1 fi S O * Q. ' r^^ __o S « 1 o+ CG a OJ o a ft 0 •a 0 O r3 'o rH C3 a § S cf • I— I • o ^ 2 *> a -(j a a '3 « r-] O) *&, rS 2 a o J/2 a rH «3 a o> -^ -S F o ^-f K^S ^-( r-^_ £ a rH j in ^ ^ O .2 2 *"» J! g1 9 s °rt o O H O rH a O K (/D EH Anceidse pyriclse ymotho B C . idge nno 8 • ^ SJ S^ i-- »pH 11 ospiraojseqdg o a O ft f ^ CO & PH :a O> O3 -rS a> O O a a o •» 9-: O ^.2 o (D H .2 -M a I ra 1 ft a CO 0 m I PM .S 1 rH O on II s B 03 _T w c3 . tj o ••§ • « | ^ S rH "* 'ft ° §! « CD • c3 a M o 4) o a o a y> fH a ^ a r= ^ O - CD O P a r-, -^ o ®.S gj H fc0 "^ * .S a •f *"c •vaojosi •— ' rH -O a H-3 a a « s JH o o ra a S « o HJ a ft 116 ISOPODA. Group— ABERRANTIA. THIS group is formed of those Crustacea which, al- though belonging in certain important conditions to the order Isopoda, offer peculiar aberrant characters. In the Amphipoda the branchial organs are (as in the Podophthalmic orders) attached to the appendages of the body. In the aquatic Isopoda they are attached to the fourth and fifth pairs of the appendages of the tail. But in the several genera which we link together to form this group, the branchial organs have not been made out ; indeed, both Dr. Fritz Miiller and Prof. Lilljeborg assert that no such organs exist. In one genus alone (and possibly only in certain individuals of that genus) we have detected a saccular appendage attached to the coxa of the third pair of pereiopoda (or fifth pair of legs), that can, we think, only be interpreted as a branchial organ similar to those which exist in the Amphipoda attached to most of the legs. Again, in Amphipoda, the heart lies beneath the dorsal surface of the body, in the Isopoda in the tail. In Tanais and Apseudes, according to Dr. Fritz Miiller, the heart is situated as in the Amphipoda. And in the embryonic condition the development is after the manner of the Amphipoda rather than that of the Isopoda. "We restrict this group to the typical genera of Dana's sub-order Anisopoda. It also corresponds with Dr. Milne Edwards' ASSELOTES HETEROPODES, to which we have added the family of ANTHURID^E. This group, in consequence of the variation in habits, we have divided into two tribes, VAGANTIA and SUB- PARASITICA. TANAID/E. 117 11 Tribe— VAGANTIA. THE non-parasitic aberrant Crustacea are distinguished from the sub-parasitic ones not only by their different condition of life but also by their having fully developed gnathopoda (and consequently possessing seven pairs of legs), of which, at least, the anterior pair is of a large size and more or less cheliferous. They form two families, Tanaida and Anthuridce. Fam.— TANAID^E. THE body in these Isopods is long and narrow. The head is confluent with the first segment of the body, the eyes are more or less distinctly placed on footstalks. The antennae vary in length. The first pair of gnathopoda, or the anterior pair of legs, are of large size and cheliferous, or terminated by a didac- tyle claw ; the second pair are of an intermediate form, but approximating more nearly to that of the pereiopoda than to that of the first pair. The eggs are borne in a sub-pectoral pouch beneath the five central segments of the body. The tail is terminated by two setaceous articulated appendages. The family corresponds with Professor Milne Edwards' tribe of Asellotes heteropodes — the Asellota heteropa of Latreille's Families naturelles. It comprises the genera Apseudes (Rfusa), Tanais, Paratanais, and Leptochelia. The last-named exotic genus is especially interesting 118 TANAHXE. from the length of the antennae (nearly equal to that of the entire body), and to the greatly elongated anterior pair of legs (nearly twice that of the antennae). It is founded upon a minute species from the Feejee Islands, and was observed by Mr. Dana to be caprelloid in its habits, attaching itself by its hinder legs to sea- weeds, and reaching out the long arms in different directions as if in search of prey. In other respects the genus is closely allied to Tanais, T. Edwardsii of Kroyer, Tidssk. iv., 1842, pi. 2, figs. 13-19, being con- sidered by Dana to belong to the same genus. This is, however, doubtful, since, according to Fritz Miiller, that species is the male of T. Saviffnyi, and it is not improbable that the female of Leptochelia may also prove to be a true Tanais, in which genus it has, indeed, been placed by Lilljeborg in his recent memoir on this family. TAN A IS. 119 ISOPODA . TANA ID^E. VAQANTIA. Genus — TANAIS. (Andouin and Milne Edwards.*) Zeuxo. TEMPLETON, Trans. Ent. Soc. ii. (1836). Crossurus. RATHKE, Nov. Acta. xx. Anisocheirus. WESTWOOD, Ann. Sc. Nat. xxvii. (1832). Generic cliaracter. Body elongated. Cephalon and first seg- ment of pereion confluent. Antennss short, subequal. First pair of gnathopoda very large, didactyle ; second pair slender, simple, and assimilating to the pereiopoda. Pleon five-jointed, fourth joint short, fifth terminated by a pair of single-branched filamentary uropoda. IN the large size of the first pair of didactyle legs, and in the confluence of the head and first segments of the body, this genus agrees with Apseudes, but the second pair of legs are slender and simple, and the tail is terminated by two short slender appendages com- posed of but very few articuli. The antennae are also short, being nearly equal in length, although the inner or superior pair are much stronger than the outer pair. The body is small and has the sides nearly parallel. The head and first segment of the body are so closely soldered together that little or no trace of their separa- tion is visible from above; the anterior portion of the head is produced into a point. The eyes are porrected on short footstalks, which are movable in the males, according to Fritz Miiller, but which, according to Van Beneden, are completely immovable. The upper or inner antennae are seldom so long as the head and fol- lowing segment; they are straight, directed forwards and downwards, and are much thicker than the lower pair ; they are formed of a peduncle which consists of three * Resume (not Precis) cl. Ent. p. 182 (without description — 1829), pi. xxix. fig. 1, " Tanais de Costa," not "Tan. Cavolini." (The reference by M. Edwards to Ann. Sci. Nat. xiii. 288, is erroneous, being intended for Rhrea.) Latr. Cours d'Ent. 403. 120 TANAIS. cylindrical joints and a rudimentary flagellum, svhich is, however, considerably elongated in some species, as in T. Edwardsii, where it is seven-jointed; according, how- ever, to Fritz Muller, the sexes differ in the structure of their antennae. A small auditory cavity exists in the first joint of the peduncle. These antennas are attenuated to the tip, which is furnished with a strong pencil of hairs. The lower antennas resemble the upper in direction and length, but they are more slender, and consist of a five-jointed peduncle, of which the first and third are short and ring-like, and the fifth is also terminated by a few hairs, within which is also a rudi- mentary flagellum. The mouth is well formed for biting. The upper lip is conical, resembling that of the Gammari, with a ridge along the medium line terminating in a produced point. The lower lip is formed of two ovate pieces fixed obliquely, united together at their extremity, leaving a triangular space between them, arising from a reversed triangular piece rounded at its base.* The mandibles are horny and elongate-triangular, terminated in a denticulated point rather incurved, with a deep impression and a movable denticulated tooth fixed be- neath the apex ; towards the base on the inner edge, is a strong somewhat squared molar tooth, truncated, and having the entire edge of the truncated part notched for chewing : in the middle of the outer edge is a small tubercle emitting a short bristle, probably representing the mandibular palpus. The inner pair of maxillas are strong, formed of a long, curved, sub-cylindrical outer portion, with the apex truncate and spinose, and a biarticulated inner division with the tip of the second * We believe this piece, represented by Savigny as described above (and more nearly agreeing with, the figure of the same organ in Gammarus than in Cymofkoa), is identical with the piece described under the name of Under- Iceben by Kroyer (Tidssk. iv. 170). TANAIS. 121 joint armed with strong setae ; these two divisions are fixed upon an oblong movable basal joint. The outer pair of maxillae, according to Savigny, consists of a pair of organs, each of which is formed of three slender oval plates lying upon each other and arising from an oblong basal joint. The pair of foot-jaws (#), closing the mouth from beneath, is of large size, brought into contact with each other along the inner edge of the basal half, the first joint being nearly square, but with the base produced at the inner angle ; the second joint is short, but swollen on the outer edge and produced within into a flat oval plate, ciliated along the margin ; the third and fourth joints respectively are nearly triangular in form, with a strong pencil of hairs on the inner margin ; and the terminal joint is slender, curved, and affixed at the apex of the preceding joint so as to rest upon its inner edge, the top and inner margin being also furnished with a long pencil of hairs. The organs of the mouth occupy nearly the whole of the under-side of the conjoined head and first segment of the body, leaving the laterally-dilated posterior angles for the insertion, on the under-side, of the base of the large first pair of legs. The first pair of legs are not only evidently very powerful organs of prehension, but are also employed by the animal for the defence of the parts of the mouth, upon which, when unemployed, they fold very closely. They are of large size and very robust, with the wrist oblong, and the hand large and sub-ovate, set on the wrist obliquely, having the infer o-anterior angle produced into a strong fixed finger, against which the movable apical finger works, forming a powerful didactyle claw. The second pair of legs are more slender than the remainder, and somewhat longer than the third pair ; the segment of TANAIS. the body, also, to which they are attached, is shorter than the remainder. They are simple in their structure, and terminated by a long, slender finger. The five re- maining pairs of legs are also simple, and gradually but slightly thickened from the third to the seventh pair, which is the thickest. The slender membranous plates forming the incubatory pouch in the female are attached to the base of several of the intermediate pairs of legs. Fritz Miiller, in his remarkable work " Fur Darwin ' (Svo. Leipzig, 1864, p. 11), gives a lateral view of Tanais dubius of Kroyer, with the second, third, fourth, and fifth pairs of legs respectively furnished at the base with a small oval plate, which he describes as the " Anlagen der blatter die spater die Bruthohle bilden." LEG OP TANAIS. We here give a figure of the fifth leg of Tanais vittatus, from the coast of Devonshire, having an appendage at its base, which we regard as a branchial sac similar to those existing in the Amphipoda, and consequently affording a proof of the nearer relationship of Tanais with that order than is possessed by any other isopodous animal. This appendage is wanting in some specimens, and its variable existence is probably a character of specific distinction in the group. Moreover, as we have found it in the largest-sized specimens, we apprehend it cannot be regarded as the rudiment of the plates that form the incubatory pouch, as Dr. F. Miiller con- siders those of T. dubius to be. TANAIS. [23 ••„ The tci.u in this genus consists of less than the normal number of segments, and carries only three pairs of yleopoda and a pair of terminal uropoda. The segments may vary in development and distinctness, being more or less fused together, in the different species. In one or more species (constituting the genus Crossurus of Rathke) two of the segments are furnished on the upper surface with transverse fascicles of long hairs, and on the under-side with two pairs of delicate oval membranous plates, strongly ciliated, supposed by Edwards to constitute the breathing apparatus, but into which F. Mu'ller affirms not a single blood corpuscle ever enters. Each pair of these plates is fixed upon a common base, and is laid transversely when at rest, thus differing from the general arrangement of these organs. The terminal segment of the body is furnished at the sides with a pair of short, slender, articulated, fila- mentary appendages, consisting, in T. Savignyi and T. Edwardsii, of a strong basal joint followed by a six or seven jointed flagellum, at the base of which is affixed a minute oval appendage setigerous at its tip. In the species which we have figured this appendage consists of only three or four distinct joints. As yet we are but imperfectly acquainted with the cha- racteristics of the species as well as with the distinction of the sexes, habits, &c. The typical species (Gammarus Dulongii, Andouin) was from Egypt, and is beautifully illustrated by Savigny in the great work on that country. In Kroyer's monograph of the genus, published in the fourth volume of the " Naturhistorisk Tidsskrift," seven species are described, namely, T. Edwardsii and Savignyi from Madeira, T. dubius from Bahia, in Brazil, T. gracilis from Spitzbergen, T. tomentosus from the Norwegian Sea, and T. Orstedii and T. Curculio from Oresund. The 124 TANAIS. last four species are described in detail in the second series of the same work (vol. ii. p. 408). In a paper on the structure and relations of the genus by Fritz Miiller (Archiv. f. Naturg. 1864, p. 1 — ) the author is, however, induced to consider that T. Edwardsii and Sawgnyi are the sexes of the same species, and that T. curculio and Orstedii are in the same condition. From the various localities in which the different species have been found, we presume that they were taken at large by dredging, and consequently are not parasitic in their habits. Van Beneden, however (who has published some observations on the genus in the fifth volume of the second series of the " Bulletin of the Academic Royale de Belgique/' as also in his " Re- cherches sur la faune littorale de Belgique," Crust, p. 93, pi. I6b, where he has given a rude figure and details of T. Dulongi), states that he obtained a male and five females of that species from the carapace of a Chelonia mydas, thrown upon the shore near Ostend, which would indicate a carnivorous condition of life for that species. In a memoir on the relation which this genus holds to the order of Isopoda,* Prof. Lilljeborg unites in this genus not only Crossurus of Rathke, but also Para- tanais and Leptochelia of Dana. By so doing he finds himself compelled to commence by separating that division of the genus which carry two branches to the posterior pair of pleopoda from those that carry but one. We think that it is more convenient, in our present state of knowledge, to keep apart as much as possible animals possessing a marked structural distinction. We therefore retain in this work Dana's genus of PARA- TANAIS. * Bidrag till Kannedomen om de inoin Sverige ocli Norrige fore Kom- mancle crustaceer af Isopodernas underordning ocli Tanaidernas familj. Af Wilhelm Lilljeborg. Upsala 1864. TANAIS V1TTATUS, ISOPODA. ABERRANTIJ. 125 TANAID^. TANAIS VITTATUS. Specific character. Body rather short, with the segments of the pleon clothed with transverse fascicles of long fine hairs. Superior antenna? thicker and longer than the inferior, three -jointed, setose at the tip. Ce- phalon and first segment of the pereion mottled with dark lines, forming oval patches; second pair of gnathopoda shorter than the following, several of the posterior pairs of legs terminated by a sickle-shaped finger, with a tooth at the middle of its inner edge, and serrated along the base. Length two lines and a quarter. Crossurus vittatus, Tanais vitlatus. RATHKE, Nov. Act. 20, pi. i. fig. 7. LILLJEBORG, Bidrag till Kiinnedomen om de inom Sverige och Norrige FSrekomniande crust, af Isop. underord. och Tanaid. famil. p. 2£ 1864, Upsala. Tanais de Costa (?). ANDOUIN and EDWARDS, Resume d'Entomologie, t. i. pi. xxix. fig. 1. Tanais Cavolini (?). EDWARDS, Hist. Nat. Crust, iii. p. 141, pi. xxxi. fig. 6. NOTWITHSTANDING the Gulf of Naples is given by Professor Milne Edwards as the habitat of T. Cavolinii, 126 TANAIS. we have but little hesitation in referring to it the specimens from the South Coast of England, Berwick Bay, and Glasgow, agreeing as they do with a specimen in the Hope Collection at Oxford, bearing the label of that name in the handwriting of, and most probably collected by, Signer Costa, in the Bay of Naples.* There are, however, several characters in which our specimens agree so closely with those described below under the name of Paratanais Dulongii, that we should not be surprised if it should be ascertained that (notwithstanding the remarkable clothing of the basal segments of the tail) these individuals should prove to be the females of the former. We were at first, indeed, disposed to regard these specimens as being the T. tomentosus of Kroyer, from the Norwe- gian Sea, but that species is described as having " omnes fere corporis partes pilis longissimis crispis obsitse," which is certainly not the case with our specimens. It must, however, be observed that some of our speci- mens of large size are entirely destitute not only of the ventral scales forming the incubatory pouch, repre- sented by Rathke and Miiller, but also of the appen- dages alluded to above as representing the branchiae according to Mr. Spence Bate. The general proportions of the animal agree with those of T. Dulongii, except that the body is comparatively somewhat more robust. The head is broader than in T. Dulongii. The relative size of the two pairs of an- tennas are shown in the above woodcut, the upper pair having a slight rudimental flagellum concealed among In his description Prof. M. Edwards describes the three first segments of the abdomen as " tres poilus lateralement," but the rudeness of his figure leads us to infer that the hairs extend to the dorsal surface of those segments. TANAIS VITTATUS. 127 the base of the terminal setae. The lower antennae are shorter and more slender than the upper, apparently four-jointed, the second joint being short, the three others of nearly equal length, but gradually becoming more attenuated towards the tip. The foot-jaws resemble those of T. Dulongii (in our figure the dilated inner plate of the second joint is omitted, having been lost in dissection). The fore legs are very large, strong, smooth, and polished, the hand produced at its lower angle into a strong immovable finger, having a very small obtuse tubercle near its base and another beyond the middle, the intervening space being filled up by a thin portion of the edge. Several of the terminal pairs of legs are furnished with a strong sickle-shaped finger, having a tooth at a little distance beyond the middle of the inner edge, the space between it and the base being denticu- lated, In the individuals which we have examined the under-side of the body is not furnished with the incu- batory pouch, nor with the short appendages observed at the inner base of one or more pairs of the legs. In others, however, as represented by Rathke, the bilobed incubatory pouch is of large size, occupies the under surface of the intermediate segments of the body, and consists of very transparent membranes, allowing the eggs to be distinctly perceived from beneath ; its posi- tion and appearance indicated in our woodcut being copied from Rathke's figure. The most striking cha- racter of the species, however, consists in the very dense pencils or fascicles of long thin hairs with which the upper surface of the second and third segments of the tail are clothed, and which are set on at right angles to the body. The terminal segment of the tail is slightly notched in the middle of the under surface of its pos- terior margin, and is furnished at its sides with a pair 128 TANAIS. of short triarticulated filaments, resembling- the superior antennae in structure, and possibly performing similar functions. We have received specimens of this species from Ber- wick Bay, captured by our late friend Dr. George Johnston, also from Mr. David Robertson, of Glasgow ; as well as a considerable number of individuals captured by Mr. Loughrin, at Polperro, who informs us that they live gregariously below high-water mark, where they protect their small colony by retiring deeply within the fissures of the slaty rocks of the coast, where they collect together a mass of material of a " leathery consistence," behind or within which they take shelter. When dis- turbed they escape, and will spring to a considerable distance. This is probably done by bringing the head and tail together and suddenly straightening themselves. Among the several specimens sent to us by Mr. Ro- bertson, was one of a very slender form ; so peculiar was it that we figured it under the impression that it was of a separate species from the present, and named it in the dredging list as T. hirticaudatus •.* But among the hundreds that wre have had the opportunity of examining from several localities, we could identify many that were intermediate between the two extremes, and con- sider it not improbable that the slender form is but a specimen that had recently cast its skin. * Brit. Assoc. Rep. 1860, p. 225. TANA1S DULONGTT, ISOPODA . A BE RR A NTH. 129 TAN AID JR. G TANAIS DULONGII. Specific character. Body smooth. Pleon destitute of fascicles of hairs. Antenna? subequal in length, the upper pair much thicker than the inferior. First pair of gnathopoda very robust ; second pair slender, and rather longer than the pereiopoda. Third pair of pereiopoda with an appendage at the base within: tail short, obtuse, terminal appendages short, three-jointed. Length not quite a 4 of an inch. Gammarus Didongii*(?) ANDOUIN, Explicat. PI. Egypte, t. xi. fig. 1.* Tanais Dulonyii (?) MILNE EDWARDS, Crust, iii. p. 142. W.THOMP- SON, in Ann. Nat. Hist. xx. p. 245. WHITE, Cat. Brit. Crust, p. 68 ? Pop. Hist. Brit. Crust, p. 227 ? A nisocJieirus Dulonyii (?) WESTWOOD, Annales Sci. Nat. xxvii. p. 330. THE type of this species, originally figured by Savigny, was a native of the coast of Egypt ; it is, therefore, with some doubt that we affirm its identity with speci- * Our outline figures P and v are copied from Savigny's plate. VOL. IT. K 130 TANAHXE. mens from the coast of Devonshire which have served for our work, although the general resemblance is so great that we prefer to consider them as belonging to that rather than to any of the species described by Kro'yer. The species has indeed been recorded, without any expression of doubt, as a native of the Irish coast by the late W. Thompson, Esq., but the specimens which were so regarded by him prove on examination to be mutilated specimens of an amphipodous crustacean. Some differences, however, exist between our specimens and Savigny's figures of the terminal portion of the body, which we are inclined to regard as arising from inac- curate drawing on the part of Savigny rather than as really existing. The body is of moderate length, smooth, and desti- tute of hairs, especially on the segments of the tail. The upper antennas are strong, porrected, and nearly as long as the large following segment ; they are composed of three joints, of which the basal is the largest and terminated by a pencil of hairs. The lower antennae (represented too highly magnified in figure c] are rather shorter and more slender than the upper pair, and five- jointed, having a very short basal and a short third joint, the fifth joint terminating in a few hairs. The large first pair of legs are terminated by a didactyle claw, of which the immovable finger is strong and truncated along its inner edge, which is slightly denticulated, whilst the terminal movable finger is slightly serrated along its inner edge. The second pair of legs are rather longer and more slender than the third pair, the five remaining pairs being nearly equal in size. The second pair of legs are gradually attenuated to the tip, the finger being slender, acute at the tip, and but slightly bent. In the third pair the terminal joints are wider ; the fifth TANAIS DULONGII. 131 pair are furnished at the base on the inside with a small movable appendage, which we consider as being the homologe of the branchial organ of the amphipodous Crustacea ; the two hinder pairs are more robust, and better fitted for prehension, with the fingers strong and hooked. The tail is short, scarcely longer than wide, and terminated by two short slender three-jointed filaments. The only individuals which we have seen of this species were sent to us from Polperro by Mr. Loughrin. ISLE OF PORTLAND, FROM THE NOTIIE, WEVMOUTII. K 9 — 132 TANAID.E. ISOPODA . TA NA 1D^. ABEREANTIA. Genus— LEPTOCHELIA. Leptochdia. DANA, U.S. Explor. Exped. p. 800. Tanais, pars. KROYER, Nat. Tidssk. vol. iv. LILLJEBORG, Bidrag till Kan- nedomen om de inom Sverige och Norrige fb'rekornmande Crust, af Isopod. underord. och Tanaid. fain. p. 25. Generic character. Animal long and slender. First segment of pereion fused with cephalon, the following six segments sub- equal. Pleon consisting of six separate segments. Eyes pe- dunculated. Superior antennae long, and terminating in an articulated flagellum. Inferior antennae very short. First pair of gnathopoda long and chelate ; " fingers slender and gaping" (DANA); second pair slender, feeble, and terminating in a long styliform dactylos. The five pairs of pereiopoda subequal in length, the three posterior pairs having the bases somewhat more robust than the two anterior pairs. Pleopoda, five an- terior pairs, biramose ; posterior pair unibrauched and multi- articulate. THIS interesting genus holds an intermediate position between Tanais and Paratanais. It agrees with the former in the general contour of the body, and with the latter in the form of the second pair of gnathopoda as, well as of the pereiopoda. The pleon has five distinct segments, each carrying a pair of pleopoda, as in Para- tanais, but it has only a single branch to the caudal pair of pleopoda attached to the sixth segment. The an- tennae are somewhat abnormal, since there is no distin- guishable peduncle. The superior pair have the first joint long and robust, the second not half as long as the preceding, the third and every successive joint is still shorter than the preceding, so that unless the first two joints of the peduncle be fused together, it is difficult to LEPTOCIIELTA. 133 determine the limits of that portion of the peduncle.* In the inferior pair the difficulty is still greater, for there are but five joints, the last being very rudi- mentary. In this respect this pair resembles that of the genus Tanais. The first pair of gnathopoda are very long, as long as (or much longer than) the superior pair of antennas. In both the species known, they have a large gaping chela, which Mr. Dana considers as a generic distinction, but which we think is very liable to specific variation. The only species hitherto referred to this genus is Leptochelia minuta, found among sea-weed and small corals in the Island of Ovalan, one of the Feejee group, the length of which is only one-tenth of an inch. * In the typical species described by Dana, the first joint is a very minute basal one, and the second very long. 134 ISOPODA. ABERRANT1A. TANAID^E. TANAIDJS. LEPTOCHELIA EDWARDSII. Specific character. Superior antennae half the length, of the animal ; inferior antennae not so long as the basal joint of the superior. First pair of gnathopoda long, robust, with gaping chela, having the infero-digital process armed with two strong blunt teeth. Posterior pair of pleopoda short, being less than half the length of the pleon. Length \ inch. Tanais Edwardsii. KROYER, Naturh. Tidsskr. iv. 181, pi. ii. figs. 13-19. DANA, U.S. Expl. Exped. p. 800. THE animal is slender and linear. The head is fused with the first segment of the body, the six following seg- ments subequal, the anterior being somewhat the smallest. The tail consists of six segments, of which the last is rather the longest and terminates in an obtuse apex. The eyes are small, round, consisting of six or seven rather large lenses, and planted on a small peduncle placed in front of the anterior margin of the cephalon, which, however, partly covers it. The superior pair of LEPTOCHELIA. EDWARDSII. 135 antenna3 are about half the lengtli of the animal, and consist of one long basal joint exceeding one-third of the whole length of the organ ; the second is scarcely half the length of the first, and is followed by a series of eight small joints, each succeeding one being shorter than the preceding. These eight small articuli are furnished on the under side with bundles of those membranous hairs which we have generally considered as being connected with the acoustic apparatus, and therefore named auditory cilia, but which Dr. V. Herisen, who has given much attention to the subject, considers as having nothing to do with the sense of hearing. The two basal joints of this organ have not these appendages, hence we think that they alone represent the three joints of the normal peduncle. The inferior pair of antennas are very short, reaching but little beyond half the length of the basal joint of the superior pair. They are small, slender, and feeble organs, generally directed obliquely downwards, and consist of five joints, the first two of which are robust and short, the two succeeding long and slender ; the apical one minute and rudimentary. They are fur- nished with a few long slender hairs. The first pair of gnathopoda are large, strong, very long, being about two-thirds the length of the entire animal, and reaching beyond the extremity of the antennae ; the three basal joints appear to be without the power of articulation, which exists most freely between the meros and the carpus ; the carpus reaches quite to the extremity of the basal joint of the superior antennas ; the propodos is longer than the carpus, and with the dactylos forms a large, gaping, pincer-like claw ; the infero-digital process of the hand is curved, and armed with two strong tuber- cular teeth ; the dactylos is also curved and feebly serrated, a minute hair springing from the anterior 136 TANAID.E. surface of every denticle. The second pair of gna- thopoda are but half the length of the first, being slender, very feeble, and terminating in a slightly curved styliform dactylos. The first two pairs of pereiopoda are formed nearly like the second pair of gnathopoda, but have shorter, therefore stronger, dactyla. The three posterior pairs of pereiopoda are reversed from the preceding in their mode of attachment, and have the basal joint more robust than that of the preceding pairs of pereiopoda ; in other respects they resemble them in form. The five anterior pairs of pleopoda are alike in size and shape ; they consist of a stout peduncle on each side, and carry a pair of oval, membranous plates, ciliated with long and strong hairs upon the outer and inferior margins. The inner plate, if we may judge from observation after death, is carried at right angles with the outer, which rests pendant in the water. The posterior or caudal pair of pleopoda consist of a single multiarticulate branch, of which the basal joint is larger than the terminal ones: it consists of nine or ten small articuli. We are indebted for this interesting addition to our British Fauna to the zeal and research of the Rev. A. M. Norman, \vho took it during the summer of 1865 among Zosterce between tide marks in Belgrave Bay, Guernsey. The distinction between this and Dana's Feejeean species exists in the latter having longer superior an- tennae, as also more slender and longer gnathopoda, which are only armed with a small rudimentary tooth on the inner surface near the extremity of the fixed finger of the great claw ; the posterior pair of pleopoda are also longer, being described by the author as equal to the pleon in length. PARATANAIS. 137 1SOPODA. TANAIDrf. ABERRANT/A. Genus— PARATANAIS. (Dana.) " Like Tanais in having the anterior feet stout and short, and the antennae without a flagellum. Caudal stylets two-branched, branches unequal, one or many jointed." DANA, U.S. Explor. Exp. p. 798. THE above is Dana's short description of this genus, which, being founded on a specimen taken in the Sooloo Archipelago, we have only an opportunity of knowing through the author's description. There are some important points in which our British specimens differ from the above description, but they appear to be rather omissions than structural differences. We therefore give our own character of the genus founded on British specimens. The cephalon is fused with the first segment of the pereion. The eyes are pedunculated. The antennas have rudimentary flagella ; the inferior pair is more slender than the superior. The first pair of gnathopoda are robust and chelate ; the second feeble and monodactyle. The pereiopoda subequal in height and resembling each other in form. Pleon having six distinct segments supporting six pair of pleopoda, five being double ovate plates with ciliated margins adapted for swimming, the sixth forming a pair of biramose substyliform ter- minal uropoda. 138 ISOPODA. ABERRANTIA. TANAIM. TANAID^. PARATANAIS FORCIPATUS. Specific character. — Body moderately long and slender. Pleon much longer than broad. Legs short. First pair of gnathopoda serrated along the inner margin of the digital process of the propodos ; second pair of gnathopoda resembling, but longer than, the pereiopoda. Upper antennfe much thicker and longer than the lower pair. Tail terminated by a pair of short, double- branched, two-jointed filaments, setose at the tip. Length one line and a half. Tanais forcipatus. Tanais Saviynyi. Zeuxo Westwoodiana ? LILLJEBORG, Bidrag Isop. Tanaid. fam. p. 25. GOSSE, Mar. Zool. i. fig. 246 (but not of KRONER, Nat. Hist. Tidssk. iv. pp. 168, 181, pi. xi. fig. 1—12). TEMPLETON, Trans. Ent. Soc. Lond. ii. 203, pi. xviii. THE eyes are planted on peduncles and terminate in an obtusely pointed apex. The inferior antennae are shorter and more slender than the superior, but scarcely so much as represented in our figure. The first gnathopoda, or chelate appendages, have the hand armed with three or four small serratures or sharp- pointed denticles, situated on the distal half of the inner margin of the digital process of the propodos. The second has the hand long and slender, the finger forming PARATANAIS FORCIPATUS. 139 an exceedingly long, delicate, tapering, hair-like point. The third and fourth pairs of appendages somewhat resemble the second, but the fingers, though fine and sharp, are are not so long and hair-like. The three posterior pairs of legs are reversed, and have their dactyla short and curved. The posterior pair of pleo- poda are biramose, both branches being nearly of the same length, and both two-jointed. The more elongated form of the body, and especially of the tail, the short legs, and the short, double-branched, two-jointed appendages of the tail, distinguish this species from its congeners. Its small size would, how- ever, seem to indicate an animal not yet arrived at full size, and which, when fully grown, might probably afford less evident distinctive characters. It is proper to observe, however, that the Tanais Savignyi of Kroyer is furnished with a pair of seven-jointed filaments at the sides of the tail, the basal joint being much thicker than the rest, and furnished at its inner extremity with a short ovate appendage, setose at the tip, about half the size of the second joint. We were at the first inclined to con- sider, from its elongated form, that it was identical with Zeuxo Westwoodiana of Temple ton, but not only is that species represented as having a six -jointed pair of anal filaments, but the antennae are nearly equal in length. In other respects the species seem identical.* The upper antennae are considerably thicker and some- what longer than the lower, and composed of three joints gradually diminishing in thickness to the tip, the first being as long as the two others united, and the * Since the above woodcut was prepared, we have received from the Rev. A. M. Norman a specimen, captured among Zosterce between tide marks in Belgrave Bay, Guernsey, which has a pair of six-jointed anal filaments with a short one-jointed secondary filament arising from the extremity of the basal joint. Can this be the female of Leptochelia Edwardsii fully grown ? 140 TANAIDJE. extremities of all the joints furnished with a few hairs. The lower antennae are four (? five) jointed and slender. The second pair of legs are slender, and longer than the following pair, with the terminal finger long, very slender, and slightly bent. The third and fourth pair of legs are very short, and the three posterior pairs longer and stronger. The tail nearly occupies one- third of the whole length of the animal, the six segments of which it is composed being distinct ; the five basal ones trans- verse, and the terminal one rounded at the extremity, which is furnished with a pair of biramose biarticulated filiform appendages, slightly hairy at the extremity of the joints. The first specimen of this species that we obtained we dredged in Plymouth Sound. It was very small, and possessed but six segments to the pereion, and conse- quently wanted one pair of legs. We therefore as- sumed it to have been that of a very young animal. We have since, from our valued correspondent Mr. Edward, of Banff, obtained two others of larger size, and with the normal complement of limbs, all the other features being persistent, a circumstance that induces us to believe that our description represents the character of an adult animal. We are compelled to adopt this conclusion, from its difference from Tanais, its nearest ally, both in the form of the second pair of gnathopoda, the number of pleopoda developed as swimming appendages, and the biramose condition of the posterior pair of pleopoda. PARATANATS RIGIDUS. ISO POD A. ABERRANTIA. 141 TANAID^E. PARATANAIS RIGIDUS. Specific character. — Body narrow. Margins of the pereion and pleou parallel, pleon terminating in a central point. Antennre not longer than the cephalon. Posterior pleopoda having both rami uniarticulate, the outer being half the length of the inner. Length £th of an inch. THE form of this species is slender and cylindrical, the sides running parallel with each other from the outer angle of the anterior margin of the head almost to the posterior pair of pleopoda. The cephalon is confluent with the first segment of the pereion, and both together form a segment that is scarcely longer than broad. The second segment of the pereion is very short ; the third is about three times as long as the second, and both together about as long as the cephalon ; the fourth segment is quadrate, and as long as the twro preceding ; the fifth is a 142 TANAIDJJ. little longer than the fourth, but about the same length as the sixth, while the seventh is about half the length of the sixth. The pleon has the first five segments subequal, but the sixth or terminal is quite as long as two of the preceding, and terminates in a central point that is furnished with a solitary hair upon each side of the apex. The eyes are small and not easily recognized. The antennae are short, the superior being more robust and slightly longer than the inferior, and tipped with a few cilia ; in length they equal that of the cephalon and first joint of the pereion, which being fused together form the head. The superior antenna consists of four joints, that is, a peduncle of three and a uniarticulate flagellum, but which is more slender and longer than the last joint of the peduncle. The inferior antenna appears to ter- minate in a similar uniarticulate flagellum. The first pair of gnathopoda are long and robust, of which the hand is not larger than the rest of the limb. The carpus is as long as the propodos, and the dactylos is long, curved, and slender, forming with the digital process of the propodos, against which when closed it impinges closely through its entire length, a sharply-pointed and somewhat elongate chela. The second pair has the dactylos long and slender, being hair-like at its extremity and slightly curved ; the remaining pairs of legs, the true pereiopoda or walking legs, are subequal in length, of somewhat slender and feeble proportions, and terminate in small curved dactyla. The five anterior pairs of pleopoda are pedunculated and liberally ciliated on the outer and posterior margins. The posterior pleopoda are biramose, the inner branch being rather shorter than the ultimate segment of the pleon j it is single-jointed, but furnished near the middle, on the inner side, with a small pro- PARATANAIS RIGIDUS. 143 tuberance armed with two or three minute cilia, and carrying at the extremity five long and strong hairs. The outer ramus is about half the length of the inner, single-jointed, armed near the middle of the outer margin with a single hair, and also with a second solitary hair on the outer side of the apex. The species bears a near resemblance to that described by Lilljeborg under the name of Tanais brevicornis. Lilljeborg describes that species as having the inner ramus of the posterior pair of pleopoda biarticulate, whereas in this it is uniarticulate, but the small ciliated protuberance near the middle of the inner margin, together with the circumstance that from that point a slight bend or change of direction takes place, may have suggested the idea of a second articulation to the author of that species, as it was a question which we could not determine until we had treated the specimen with " liquor potasses.3' So well, otherwise, does this animal correspond with Lilljeborg's description, except in the number of joints of the upper antenna, that had it been described by any less experienced observer, we should have considered the two as belonging to the same species, assuming that the points in question had been misinterpreted. The only specimen that we have seen of this species was sent to us by Mr. Robertson, of Glasgow, who " dredged it at the roots of Laminaria saccharina" near Cumbrae. 'A 144 TANAIDJE. ISOPODA. TANAIDJ&. ABERRANTIA Genus— APSEUDES. Apseudes. LEACH, in Brewster's Edinb. Encycl. vol. vii. p. 404, 1812. EDWARDS, Hist, des Crust, t. iii. p. 138, 1830. LILLJEBORG, Bidrag. kan om de inom Sverige och Norrige forek. Crust, af Isop. Tanaid. fam. p. 8, 1864. Eupheus. Risso, Hist, des Crust, des Nice, p. 124, 1816. Rhcea. MILNE EDWARDS, Ann. Sci. Nat. xiii. p. 292, 1828. Generic character, — Body elongated. Head and first segment of the pereion confluent. Upper antennae longer than the lower, with the first joint of peduncle long and robust, the flagellum consisting of two elongated articulated filaments. First pair of gnathopoda chelate ; second pair having the propodos trans- versely dilated. Pleon terminated by a large segment bearing two long and two short slender filaments. THE head and first segment of the body are confluent, the former advanced in front into a point, forming a small triangular rostrum, the latter having the sides dilated and depressed. The eyes are large and borne on movable footstalks. The upper antennae are robust, the first joint especially being long and stout ; the flagellum or terminal portion is multiarticulated, and provided at its base with a slender secondary filamentous appendage composed of numerous articuli ; the lower antennas are shorter and more slender, furnished with a small squamiform movable process, as in the Ma- crourous stalk-eyed Crustacea, and terminate in an articu- lated and gradually attenuated flagellum. The mandibles are small, slightly truncate, denticulated at the ex- tremity, and furnished with a three-jointed palpiform appendage. The outer foot-jaws are confluent at the base, and terminated by three flattened joints strongly ciliated. APSEUDES. 145 The first pair of legs are robust, terminated by a strong didactyle hand. The second pair, though smaller than the first, are more robust than the following, being flattened and terminated by a broad hand-like joint, more or less palmated, the penultimate joint (propodos), having a small movable finger (dactylos) ; the five following pairs of legs are slender and simple. The five segments of the tail are short, but the last (sixth segment) is elongated, and terminated by a rounded plate (the telson), on each side of which is placed a flattened appendage, termi- nated by one long and one short very slender filiform branches, being the representatives of the last pair of tail-feet. The five anterior segments of the tail are respectively furnished with a pair of appendages, each consisting of a basal stem supporting two delicate folia- ceous plates strongly ciliated along their margins. The eggs are borne in a semi-transparent pouch beneath the breast, which extends from the second to the sixth segment of the body. This is one of the most interesting genera of crus- taceous animals. In some respects, such as the form of the eyes, the articulated filament attached to the upper-, the squamiform process of the lower- antennae, and the cheliferous anterior feet, we perceive a relation- ship to the macrourous stalk-eyed order of Crustacea; in other conditions it assimilates the Amphipoda, in which order Professor Milne Edwards was at the first disposed to place it, although he subsequently referred it to the Isopodes Idoteides (Encyclop. portatif. p. 182; Ann. Sci. Nat. 1830, August), induced to this step by the struc- ture of the breathing apparatus, which he attributed to the under side of the segments of the tail ; whilst the soldering of the head and first segment of the body, and the podophthalmous structure of the eyes, induced VOL. II. L 146 TANAIDyE. Dr. Fritz Miiller (Archiv. f. Naturg. Jahrg. 1 Bd. p. 1) and Van Beneden (Ueber der Bau der Scheerenasseln Assellotes Heteropodes M. Edw.) to attribute it to tbe Macrourous Decapods, each basing bis opinion, arrived at independently, upon the supposition that the union of the head with the first joint of the body is an incipient effort in the development of a carapace — the latter author, moreover, asserting that respiration is carried on beneath the carapace, although he states that he has not been able to detect any especial organ adapted to that purpose. From this view of the question we must entirely dissent, first, because the branchial organs in decapod Crustacea are essentially appendages of the coxae or first joints of the limbs attached to the pereion or pleon: consequently, all these limbs being posterior to the cephalon, the organs of respiration cannot be developed beneath it ; second, because the carapace is not developed by a fusion of the segments of the pereion with those of the ce- phalon, but by a monstrous production of the integu- ment of the latter extending back, over, and covering the segments of the former ; and so, in the typical decapoda, overlying and protecting the segments of the pereion, and consequently the branchial organs also. This genus also approaches towards the Podophthalmous Crustacea, and more particularly the Macrourous order, in the form of the eyes and inferior antennae, whilst it re- sembles the Amphipoda in the character of the legs and the general slenderness of the body. It also approaches the Squillte in the character of the pleopoda, and the Isopoda in that of the posterior pair of pleopoda. One interesting and, as far as we know, unique feature in these Crustacea yet remains to be noticed. The segments of the pleon have the lateral walls (long known as the APSEUDES. 147 epimera of Milne Edwards, called also the pleura by many authors) existing as articulated appendages, demon- strating two important features in the homologies of these parts : first, that they are really portions of the appendages, being the first joint or coxae of the pleopoda, as first observed by Mr. Spence Bate in his report on the Amphipoda ; and second, that since the peduncle consists of three joints, the second branch in the appendages of the pleon, as in other parts, is shown to take place in- variably at the extremity of the third joint. Of this genus we regret that we have obtained but few specimens, too few, indeed, to have enabled us to make complete dissections of the animal. As yet we know not the form of the male animal ; it may be similar to that which we figure as the female, but had not Miiller, Rathke, and Lilljeborg described the females of Tanais as resembling the male, we should have suggested that these species were females of Tanais, for it is a singular fact that although of the latter genus we have examined some hundreds of individuals, we have never yet seen one possessing the features of a female.* * We are bound, however, in this place to recall attention to Rathke's figure of his Crossurus vittatus with a large incubatory pouch filled with large eggs. L 2 148 ISOPODA. ABERRANT!^, TANAID.E. TANAID^E. APSEUDES TALPA. Specific character. Front of cephalon terminating in a porrected point, its dorsal surface irregular. Body finely but sparsely setose. Pleon very hairy at the sides. Terminal segment of the pleon long and slender. First pair of gnathopoda large ; the carpus with two lobes on the under edge. Palm of the propodos with a tooth in the middle ; dactylos with a tooth at its base. Length one -third of an inch. • Cancer (Gammarus) Talpa. MONTAGU, Trans. Linn. Soc. ix. p. 98, t. 6, f. 6. Apseudes Talpa. Eupheus Talpa. LEACH, Edinb. Enc. vii. p. 404. Trans. Linn. Soc. xi. p. 372. Suppl. Enc. Brit. i. p. 428. SAMOUELLB, Ent. Compend. p. 109. LAMARCK, Hist. Nat. Anim. sans, vertebr. v. p. 290. MILNE EDWARDS, Crust, iii. p. 140. CUVIER, Regne An. Edit. Crochard Crust, pi. 62, fig. 1. WHITE, Brit. Mus. Cat. Brit. Crust, p. 67. Pop. Hist. Brit. Crust, p. 226. GOSSE, Man. Mar. Zool. i. fig. 245. DESMAREST, Cons. Crust, p. 285, t. 46, fig. 9. APSEUDES TALPA. 149 THE figure of this species, published originally by Montagu, and which has been copied by all subsequent authors (except Prof. Milne Edwards), was so ill drawn, that the true relations of the animal could not possibly be determined. The head and first segment of the body were confounded together into a triangular mass, desti- tute of any trace of articulation, and the tail was repre- sented as elongate-conic in form, and composed of twelve very short joints, all being very setose. The figure given by Prof. Milne Edwards, quoted above, was made by him from the original specimen of Montagu, preserved in the British Museum, and represents the animal more faithfully ; the lower antennas are, however, drawn too small and short, a sketch made by us from the same individual many years ago, representing the an- tennae as nearly equal in length — possibly from the flagellum of the upper pair being broken off; neither does Prof. Milne Edwards's figure give a correct idea of the dilated structure of the second pair of hands. The segments of the body are transverse, serrated along the hinder margins, the sides being rounded ; the five basal segments of the tail are very short, the sixth being as long as all the rest together, and terminated in an obtuse point, at the sides of which are affixed the terminal pair of tail-legs, which are transformed into a very long setaceous filament, having a shorter one at its base. The segments of the tail are very pilose at the sides. The upper antennas have a strong basal joint, crenulated along its inner edge, in the middle of which is a small, setose swelling; the following joint is strong, but very much shorter than the preceding, followed by a smaller joint, and the terminal filament, or flagellum, is very slender and multiarticulate, the secondary filament at its base being half the length of the primary one, and 150 TANAID^E. also composed of a considerable number of articuli. The lower antennae are much shorter than the upper, the basal joints being the thickest, the third furnished with a small oval squamose plate at its extremity, the terminal joints or flagellum slender, extending beyond the base of the flagellum of the upper. The upper surface of the head is uneven (the fissures probably marking the point of fusion of the head \vith the first joint of the body), terminating in front in a porrected point. The eyes are affixed upon a pair of short, somewhat kidney- shaped lobes. The outer foot-jaws are short, and ciliated on the inner margin. The mandibles are elongated, gradually narrowing to the tip, which is denticulated ; they bear a slender, three-jointed appendage, the first joint of which is very short, the second and third longer and nearly equal in length, the latter furnished with long bristles at the tip, set on at right-angles to the joint. The first pair of legs are robust, the wrist is swollen, and armed on its under side with two tubercles a short distance apart ; the hand is large and oval, its inferior angle produced into a finger, having a tubercle on its inner edge near the middle, against which the true finger impinges, the latter having a small tubercle on its inner edge, close to its base. The second pair of legs have the hand developed into a large, transversely flattened ovate joint, having several strong spines on its margins, so as to give it a digitated appearance, the terminal finger resembling one of these spines. The third and fourth pairs of legs are slender, having a forward direction, the penultimate joint is very slender, except at the tip, which is dilated and fringed with spinous hairs, the slender terminal finger inserted on its posterior surface within the tip. The fifth pair of legs are also slender, but with a back- APSEUDES TALPA. 151 ward direction (as have also the sixth and seventh pairs) ; in all these legs the hand is armed near the base of the under margin with a strong spine, against which the extremity of the finger, when closed, impinges, this joint being dilated in the two posterior pairs, and strongly ciliated along both its inner and outer margins and apex, the finger being planted anteriorly within the palm of the concave hand. The ventral appendages of the five segments of the tail are free, consisting, in each segment, of two pairs of delicate, elongate-ovate plates, each pair attached to a basal, three-jointed footstalk, the first joint of which consists of a plate, having the posterior margin serrated and furnished with several long bristles, the anterior margin being fringed with plumose hairs, as also the inner margin of the third joint, as well as both those of the subtending plates. The sixth segment is semi-ovate, and furnished at each side with an appendage formed of a single-jointed pe- duncle, supporting one long and one short filamentary branches formed of numerous articuli, increasing in length as they diminish in size towards the distal ex- tremities. We only know the female of this species. The incubatory pouch is formed of very slender, semi- transparent plates, which permit the large eggs enclosed to be distinctly visible. The general colour of the animal, when alive, is yellowish-w7hite, the hairs and divisions between the seg- ments of the body partaking more of the former colour. Colonel Montagu took this species on the large scallop (Pecten maximus) at Salcombe, on the South Devonshire coast. It has also been taken off Guernsey, by the Rev. -• 152 TANAID^. A. M. Norman, and we have taken it, in company with the late Mr. Barlee, in Plymouth Sound. Mr. W. P. Cocks found it, rarely, amongst Sertularia and other trawl refuse, in the middle of the month of April. o APSEUDES TALPA. (EXTREMITY OF FEET.) APSEUDES LATREILLII. 1SOPODA. A li ERRANT! A. 153 APSEUDES LATREILLII. Specific character. Body smooth, destitute of hairs on the sides. Head terminating in front in a deflexed point. Terminal segment of the tail not more than half the length of the preceding portion of the pleon. First pair of gnathopoda moderately large, the hand produced at its lower angle into a strong linger, which is densely hairy, but destitute of tubercles or spines, as is also the true movable finger. Length one-fourth of an inch. Rhcea Latreillii (?) MILNE EDWARDS, Ann. Sci. Nat. V. xiii. p. 288, pi. ISA. THE specimen from which the accompanying figure is drawn bears so great a resemblance to Milne Edwards^s figure of Rhcea Latreillii that we have no doubt as to the identity of the two animals. The deflexed rostrum, or advanced point of the head, the comparatively large size of the second pair of feet, the more slender hand with the smooth fingers in the first pair of limbs, are all characters observable in both. The small central point of the head, or rostrum, is slightly down-curved. The orbital process is produced to a pointed apex. The superior antennae have the pe- duncle smooth, and the secondary appendage of the flagellum scarcely half as long as the primary. The inferior antenna reaches but little beyond the peduncle 154 TANAID.E. of the superior. The first pair of hands hate the carpus rather longer than the propodos, and ciliated along the inferior margin ; the propodos has the inferior digital process liberally ciliated over the surface, and more so along the margins ; the dactylos is curved, smooth, and inversely corresponding in form to the margin of the opposing finger. The second pair of hands have the margins of the carpus and propodos fringed with strong spines, and the finger planted in the middle of the ex- tremity of the flattened propodos. The succeeding legs appear not to differ much from those of the preceding species, except the posterior pair, which, instead of having the propodos fringed with cilia, have it armed with short, stiff spines, that increase in length towards the distal extremity. In most other points this species appears to differ but little from the preceding. We have seen but a solitary specimen, which was sent to us by our esteemed correspondent the Rev. A. M. Norman, who obtained it on the coast of Northum- berland. This specimen was a female, and carried a mass of large, circular, orange-coloured eggs between the second and penultimate segments of the pereion, beneath a transparent membranous sac. M. Milne Edwards first described this species in the Ann. des Sci. Nat. t. xiii. p. 288, pi. 13A, fig. 1-8, from a specimen dredged on an oyster-bank of Port Louis ; but in his description in Hist, des Crust, t. iii. p. 141, he gives the coast of Brittany as the habitat. The extreme paucity in the number of the specimens both of this and the preceding species, that have been recorded, induces us to believe that the true habitat and habits of the genus have yet to be discovered. ANTIIURID^. 155 1SOP ODA . A NTH URIDtf, ABfiRRANTIA. Fam.—ANTHURID^E. (Anthurada— Leach.} THE animals in this family are very long and slender, the head distinct from the pereion, the antennae very short and nearly equal in length, the first pair of legs large and subchelate, the remaining six pairs nearly equal in size and uniform in shape, the pleon furnished with biramose squamose appendages, terminal pair of pleopoda transformed into a pair of scale-like appendages at each side of the terminal joint. The head is nearly oval, with the eyes small, oval, formed of but very few lenses, and placed near the anterior angles of the head, behind the antennae, which are very short and gradually attenuated to the tip. In the figures in page 160, they are represented as they appeared to us under a lens, in the very ill-preserved type of the genus, originally described by Montagu, now in the British Museum. In specimens preserved in spirit of a second species, contained in the Hopeian Collection, the upper pair are placed a little apart at the base, whilst the lower pair, which are the most robust, arises close together, their basal joint being por- rected and brought into contact with each other along their inner edge, thus forming a protection from above to the oral organs. The upper pair of antennae are composed of a three-jointed peduncle and a four-jointed flagellum, the terminal joint furnished with a long pencil of hairs at the tip. The lower, and more robust pair, consist of five joints, of which the second and third are shorter than the first and fourth; the terminal joint is conical, and furnished at its tip with a pencil of hairs. 156 ANTHURDXE. The mouth, of which the peculiar structure has been overlooked by all previous writers, is evidently formed for suction, and consists of a narrow process extending along the anterior half of the under side of the head, and porrected in a point in front.* The mouth is closed beneath by a pair of foot-jaws, each composed of two oblong, flattened joints, the second of which is slightly curved and somewhat pointed to the tip, and armed along its inner edge with a series of long hairs. Within this pair of foot-jaws appear two long and extremely slender, nearly straight, setae, of which the extremity, along the inner edge, is finely retro-serrated. We regard this pair of organs as the second pair of maxillae, very similar in general structure to those of the genus &ga and its allies. We have found no trace of the first pair of maxillae, but the mandibles appear to be represented by a pair of elongated, pointed organs, having a three-jointed palpus, bearing a close general resemblance to the mandibles and their appen- dages in Limnoria, Mga> &c. These organs rest within or beneath an elongated, conical, horny piece, of which the tip appears to be deeply bi-sinuated, forming the upper lip, and within the mouth we find another elon- gated, single organ, thickened at the base, which may possibly represent the * levre inferieure' of Savigny. The seven following segments of the body are quite distinct, the anterior ones being the longest, whilst the last, or seventh, is the shortest of them all. The incu- batory pouch in the females extends from the second to the seventh segment. The tail is composed of six segments, the four an- This description is made from individuals of the second species, above alluded to, to which the name of Par. Costana has been applied by Prof. Westwood. ANTHURA. 157 terior of which are soldered together ; die fifth is a small segment with the hind margin raised and notched in the middle, and which supports the latero-caudal plates ; and the sixth forms the large terminal central plate of the tail. The family comprises three genera, of which the two following are British. Genus— ANTHURA. (Leach.) The body is very slender, elongated, and somewhat triquetrous, having the head and segments of the body quite distinct from each other ; but the four anterior SHAPE OF BODY. segments of the tail are confluent, and so closely attached together, that, in fresh specimens, or in those preserved in spirits, the articulations are not recognizable; the penultimate segment of the tail is short, having on each side a pair of scale-like appendages, representing the terminal pair of tail-legs. The pleopoda consist of, at least, four pairs of oval plates, strongly ciliated, on each side of the ventral surface of the basal segments of the tail. They are of nearly equal size, and arranged so as to lie longi- 158 ANTHURID^. tudinally, but, in the first pair alone, the outer division is very much narrower than the inner division. The terminal pair of tail-feet are transformed into a pair of crustaceous plates, affixed to each side of the penultimate segment at its base ; the inner plates have a transverse articulation beyond the middle,* and the outer plate is affixed vertically and falls back, when at rest, upon the dorsum of the terminal joint, fitting into the de- pression formed by the transverse carina on that segment. The lower figure, P z> in page 160, represents the lateral view of the tail of A. gracilis, being the four basal seg- ments (represented as entirely soldered into one joint), beneath which is seen three pairs of tail-feet in a mass, the long appendage arising from the lower anterior angle of the segment representing the anterior large pair that covers the rest as an operculum ; the fifth segment of the tail is also shown as distinct, followed by the large laterally-deflexed portion of the terminal pair of tail-feet or scales which it supports ; the articulated extremity of the two inner divisions of this pair of appendages, and the truncate extremity of the middle portion of the tail being also shown in the deflexed portion of the figure. The left-hand figure, P", represents the ventral surface of the two terminal segments of the body, and of the tail, showing the inner division of the anterior pair of tail- feet, concealing the outer division of the same pair as well as the whole of the remaining pairs of the organs. Fig. p represents the outer division of the left-hand pair of the first respiratory tail-feet, and fig. p", a portion of its lateral, deeply ciliated margins, showing the in- sertion of the ciliae. The anterior pair of feet are strong but short, not ' In jEya this articulation is oblique, and extends to the insertion of the outer plate. ANTHURA. 159 extending beyond the front of the head ; the hand is ovate, protected at the base of its inner margin by the produced extremity of the preceding joint ; the finger is strong, and terminated by a distinct unguis. The six other pairs of legs are much more slender and simple, terminated by a short, rather strong, curved finger, and a distinct terminal unguis. The very elongate and slender form of the animals of this genus gives them a certain amount of resem- blance to the species of Arcturus, and has led to their being placed in the family of which Idotea is the type ; but Dr. Leach long ago had the tact to perceive their claims to form a distinct family, and, although their general form, short antennae, and strong fore legs, give them a certain similarity to Tanais, yet we apprehend (now that their real structure has, for the first time, been described from a minute analytical examination of their oral organs) that their true affinities will be admitted to be in o / the immediate neighbourhood of the ^Egida, one species of which at least, Conilera cylindracea, approaches them in its elongated cylindrical form ; indeed, Dr. Leach suggested that this animal might possibly be referable to the family Anthurida, and, accordingly, in Mr. White's catalogue of British Crustacea, it is placed as a second species under the name of Anthura cylindrica, appearing again in a subsequent page, in its proper place and name, as Conilera cylindracea. 160 ISOPODA . ABERRANTIA. ANTHURID.E. ANTHURID^E. J ANTHURA GRACTLIS. Specific character. Long, slender, sub-compressed, sub -cylindrical. Seg- ments of the body with a strong, lateral ridge ; terminal segments sub-trian- gular. Four anterior segments of the pleon soldered closely together, forming a subtriangular mass ; middle tail-piece keeled down the centre, with three very delicate, longitudinal, raised lines, down the sides of the keel ; apex truncate ; apex of the inner division of the lateral scales obliquely truncated, and crenulated. Length 5 lines. Oniscus gracilis. MONTAGU, Trans. Linn. Soc. ix. p. 103, t. 5, fig. 6. Anthura gracilis. LEACH, Edinb. Encyc. vii. p. 604. Trans. Linn. Soc. xi. p. 366. Suppl. Enc. Brit. DESMAREST, Cons. Crust, p. 291, t. 46, fig. 13. SAMOUELLE, Entom. Compend. p. 107. GUERIN MENEVILLE, Icon. R. An. t. 30, fig. 6. MILNE EDWARDS, Crust, iii. p. 136, t. 31, fig. 3. WHITE, B. M. Cat. Brit. Crust. p. 67. Pop. Hist. Brit. Crust, p. 225, pi. 12, fig. 4.* GOSSE, Man. Mar. Zool. i. fig. 248. In this figure two segments of the body and one of the pairs of legs are omitted. ANTHURA GRACILIS. 161 Tins species is well defined by the strong, raised, lateral margins to the segments of the body and tail, by the consolidation of the basal segments of the latter almost into a solid mass, the articulations being, how- ever, clearly indicated by impressions on the under edge of the lateral margin, and especially by the characters of the terminal segment of the tail and its appendages, noticed in the specific characters given above. It is, however, rather difficult to describe precisely the curious construction of this terminal portion of the body. Montagu says that " the body is terminated by five large caudal appendages truncated at their ends, these are deflected nearly at right-angles with the body, the middle one fixed, and the lateral ones jointed and spread a little upwards in a semicircular form." The last term is not, however, at all expressive, and should, doubtless, have been " seniicylindrical," since the ap- paratus, when open, forms a concave cup-like disc, and when at rest, from being affixed vertically, the outer plate falls back and shuts down upon the dorsum of the middle tail-plate, like the two wings of a closed triptych. The irregularly crenulated margin of the extremity of these caudal plates also affords another distinctive cha- racter. Not having seen fresh specimens of this species, we are unable to give a more precise description of the antennae than is conveyed in our generic observations. The fore legs, although not longer than the succeeding pairs, are very much more robust, with a large, elongate- ovate hand, the upper basal angle being swollen, and the palm having a deep incision along its outer half (which we believe to be caused by the elongation of the outer and lower angle of the preceding joint) which is slightly rugose. The other legs are much more slender, with the joints of nearly equal length, the fifth and sixth having VOL. II. M 162 ANTHURID.E. a small spine at the extremity of the under margin ; the terminal dactylos also ends in a small, sharp-pointed unguis. The colour of the animal is pale yellow, clouded with rufous. The species was first taken on the Coast of Devon- shire, by the late Colonel Montagu, and since by Mr. Barlee, at Falmouth, and off the Thatcher Rock, Torbay, by Mr. Walker, of Exeter. The following vignette represents some fishermen drawing in a seyne full of fish, on most of which these Crustacea attach themselves. SEYNING. PAKANTHUKA. 163 Genus— PARANTHURA. OUslca (?). Rrsso. HOPE. Generic character. Like AntJntra, except in the structure of the pleou, which has the several segments distinctly articulated with each other, and carries the normal number of pleopoda. THE animal is long, slender, and linear ; the head distinct from the first segment of the body, the latter consisting of seven segments, the whole being nearly subequal, except the last, which is shorter than the preceding. The tail is short, being about one-eighth of the length of the entire animal, consisting of seven separate segments, six of which support appendages. The eyes are sessile and ovate. The superior pair of antennas are short, being about the length of the head, each being formed of six joints, gradually diminishing in size to the last. The inferior pair is longer and much stronger than the superior, and five-jointed, the large basal joint being attached to the head by a short, indistinct joint ; the second, third, and fourth joints gradually increase in length, the fourth being not quite so long as the basal joint; the fifth joint is nearly as long as the fourth, and gradually attenuated to the tip, furnished with long setae, and terminated by a very minute, exarticulate point. The three anterior pairs of legs (namely, the two pairs of gnathopoda and first pair of pereiopoda) are formed upon the same type, and terminate in a sub- chelate hand. The four posterior pairs of legs are more slender, and attached in an opposite direction to the anterior pair. Each of the tail appendages (or pleopoda) consists of two membranaceous plates for respiration ; M 2 164 ANTHURHLE. the first pair are large, and have the external branch narrow, and attached so as to lie upon the outer margin of the other, which is ovate and foliaceous ; the four pairs next succeeding are ovate, membranous, and folia- ceous. The posterior pair are articulated to the sixth segment dorsally. The upper and outer branch is folia- ceous, and affixed vertically ; the inner and inferior branch is two-jointed, and placed horizontally below the plane of the middle tail-piece, which is ovate, and terminates in an obtusely pointed apex. There is a species of this genus, an inch in length, in the Museum of the Jardin des Plantes, from Port Western, New Holland. PARANTHURA COSTANA. ISOPODA. ABERRANTIA. 165 ANTHURID^. PARANTHURA COSTANA. Specific character. Cylindrical ; segments of the body of nearly equal size ; middle tail- piece not carinated, ovate at the extremity ; inner branch of the sixth pair of tail appendages articulated and rounded at its extremity. Hand of the first pair of legs produced into a minute, reflexed tubercle at its extreme inner base. Anthura gracilis. MILNE EDWARDS, Hist, des Crust, iii. p. 136, pi. 31, fig. 3, but not of Montagu, ut supra. Idotea penicillata. Risso, Hist. N. Crust. Nice, 1816, p. 137, pi. 3, fig. 10 (?). DESMAREST, Crust, p. 315. OlisTca penicillata. Risso, Hist. N. Eur. Merid. 5, p. 113. HOPE, Cat. Ital. Crust, p. 27 (?). IN the Hopeian Collection of Crustacea are preserved several specimens of this species, fixed on card, to which is attached a label " S. W. Coast of England on Broad Sea Weed." It differs from A. gracilis in its more cylindrical form, the sides of the body wanting the raised lateral margins, the distinct articulation of the 166 ANTHURHXE. five basal segments of the tail, the smooth surface of the middle tail-piece, oval at its extremity, the very distinct and oval terminal division of the inner plate of the side appendage of the tail, and the smaller and narrower size of the outer division. The hand of the fore pair of legs also wants the notch along its under edge. It is of a pale bone colour, covered with minute black dots. The mouth is enclosed between horny plates (*f-) and furnished with a pair of straight, elon- gate-conic mandibles, pointed at the tip, having a large, three-jointed, palpiform appendage fixed at its base on the inner edge. The maxillae consist of a pair of long, very slender, slightly curved, lancet-like pieces, retro- serrated at the apex, and the mouth is closed beneath by a broad pair of foot-jaws, which are terminated by two large, flat joints, the apical one being strongly ciliated. In all these particulars it perfectly agrees with other specimens preserved in spirits in the same collection, with a label inscribed " Anthura gracilis," in the hand- writing of Signer Costa, of Naples, with whom Mr. Hope was long in friendly communication upon the marine animals of the Meditermnean. On referring to Mr. Hope's catalogue of the Mediterranean Crustacea, we find only one species of Anthura indicated \vith the name of A. gracilis, which, from a copy marked by S. Costa, we find to be in his collection ; and we have, therefore, no doubt that the species was communicated by him to Mr. Hope. We therefore at first hesitated to consider the species as a real native of this country (fearing some confusion might have occurred as to the labels of the South Western Coast specimens), and, in honour to Signor Costa, we proposed for the species the name of Paranthura Costana. Whilst, however, this PARANTHURA COSTANA. 167 sheet was in the printer's hands, we had the pleasure to receive from the Rev. A. M. Norman, specimens taken by himself off the Channel Islands ; so that the claim of the species to be regarded as British is fully confirmed. The figure given by Mr. Milne Edwards in the work above referred to as A. gratilis, is no doubt intended for this species, since it was taken on the neighbouring coast of La Manche. But, since he mistook it for Anthura gracilis, the retention of his specific name, founded, as it was, in error, would lead to confusion ; we have therefore thought it desirable to adopt another not open to the same objection. BRIGHTON FISHERMEN. 168 ANCEID.E. ISOPODA. ANCEIDJE. ABERRANTIA. ANCEID.E. Praniziens. MILNE EDWARDS. Pranizidce. DANA. Pranizadce. VAN BENEDEN. Decempedes. LATREILLE. (Males) Gnathides, GnatJtonii, Gnathionii. LEACH. Anceens. MILNE EDWARDS. (Females) Praniziens pro})- dites. MILNE EDWARDS Pranizidce. WHITE. DANA. THE head has the first (or more probably the first and second) segments of the body fused with it ; it is very large, and flattened, or dorsally concave in the males ; quadrate or ovate, and of moderate size, in the females. The antennas are small or of moderate length, nearly equal, inserted widely apart, composed of a three-jointed peduncle and an articulated flagellum. The mouth is very anomalous in its structure, differing very greatly in the adult from the young, as well as in the opposite sexes of the same species. In the adult males the front of the head is armed with a very large pair of porrected mandibles ; in the early stages the mouth in both sexes is suctorial in its character. The body is composed of only five segments, of which the three posterior are soldered together in the females, so as to form a large, oval mass. There are only five pairs of slender, simple legs. The pleon is of small size and narrow, but well developed, consisting of six segments, of which the last is small and triangular : each segment being provided on its ventral surface with a pair of delicate, membranous, biramous, squamiform appendages, which are entirely free, and not covered by a larger anterior pair or oper- culum. The terminal pair on each side form, with the ANCE1D2E. 169 middle tail-piece (telson), a five-lobed organ useful in swimming to guide the animal. The animals composing this most anomalous family have, until quite recently, been considered as forming, not only two distinct genera, but even have been ar- ranged by M. Edwards and Dana as distinct tribes. The observations of M. Hesse, of Brest, however, leave no room to doubt that the two supposed genera, Anceus and Praniza, are but the males and females of one genus, although his assertion that they 'are but different phases of one and the same animal cannot be ac- cepted. It seems, however, sufficiently proved, that one of these animals of small size, which would hereto- fore have been unhesitatingly called a Praniza^ if kept in confinement, becomes developed into a female (Praniza}, while a second, only slightly differing, becomes a fully developed male (Anceus). We therefore adopt the sug- gestion of M. Hesse (not indeed for the reason which he assigns, that a Praniza is transformed into an Anceus — a statement which our observations will sufficiently dis- prove), but in conformity with the usual rule of priority, as well as that of accepting the denomination of the male rather than that of the female animal, and, ac- cordingly, retain for the group the family name of Anceidte. Strictly speaking, however, the name Gnat- hiidae should be given to the family, Leach's name Gnathia having the priority in point of date over that of Anceus; but as Leach himself omitted the genus in his later works, and there is a well acknowledged genus, Gnathium, amongst the heteromerous beetles proposed by Kirby, we have preferred using the generally adopted name of Anceus. : ~. •***• '-• 170 ANCEID.E. I SOP ODA . A NCEIDJ!. ABERRANTIA. Genus— ANCEUS. Gnatkia. LEACH, Edinb. Encyc. (male). Anceus. Kisso, Crust, des Nice, p. 51, 1816 (male). DESM. Praniza. LEACH, MSS. Risso, LATR., LAM., DESM. (female). Generic character. Male. Cephalon large, broad, quadrate. Pereion having the first two segments absent, or fused with the cephalon ; the two next separated from the three posterior. Pleon with six segments, the posterior terminating acutely. Eyes large and placed at the antero-lateral angle of the head. Antennas simple, subequal Mandibles anteriorly produced from the anterior margin of the cephalon. First guathopoda wanting. * Second pair of gnathopoda transformed into the outer appendage of the mouth. Pereiopoda subequal, the three posterior pairs reversed. Pleopoda biramose, posterior pair planted on each side of the caudal segment. These are the characters of the animals long known onlv as Anceus. jo •/ Female. Cephalon small, quadrate. Pereion having the first two segments wanting or fused with the cephalon, the two suc- ceeding distinct, small, subequal; the three last fused together. Pleon as in the male. This character distinguishes the animals long known as Praniza. THE history of this genus is so remarkable as to merit a detailed account. The earliest record of one of these animals is contained in the microscopical work of Slabber, tf Natuurkundige Verlustigingen," republished at Nu- remberg in 1775, under the title of " Physicalischen Belustigungen," 4to, p. 31, pi. 9, where the author gives the representation, and " Wahrnehinung ernes Oniscus marinus," being a satisfactory figure of a Praniza, which he bad found on the shores of Holland, during four months of the year, in considerable quantities, and which exhibited great agility in the water. This figure was copied by Latreille in the great " Encyclopedic Metho- ANCEUS. 171 clique, Crustaces," pi. 329, fig. 24, and described in the text as " Crustace du genre Praniza du Docteur Leach." In the seventh volume of the " Transactions of the Linnean Society," Col. Montagu published the descrip- tion and figure of an animal under the name of Cancer maocillariSy which proves to be the male of this genus; and in the ninth volume of the same work, he also pub- lished a figure and description of a female, under the name of Oniscus c&ruleatus.* In " The Edinburgh Encyclopaedia," vol. 7, Dr. Leach, in adopting the Latreillian principles of classification to the Crustacea, proposed the generic name of Gnathia for the Cancer maxillaris. He had previously, as above stated, proposed the MS. name of Praniza for the female. In " Hist. Nat. des Crust, de Nice," 1816, p. 52, pi. 2, fig. 10, Risso subsequently described the male of a Medi- terranean species under the name of Anceus for'fcularis. In the fifth volume of " London's Magazine of Na- tural History," the late Dr. Johnston published some observations on the genus Praniza, and added the descrip- tion and figure of a second species, Praniza fuscata, observing that these animals, by means of their legs, are able to creep on the bottom of the sea, which they do slowly, but they swim with greater rapidity, pro- pelling themselves forward by the quick motions of the series of ciliated fins placed beneath the tail. The remarkable structure of what is supposed to be the respiratory apparatus of these animals (intermediate as it is between that of the typical Amphipoda — namely, a series of free appendages — and that of the typical Isopoda — in which the appendages are enclosed by a bivalve operculum), induced Professor Westwood to com- * This figure was also copied in the Encyclopedic Methodique, pi. 336, fig. 28, but under the erroneous name of Oniscus (Ccelino) thoracicusof Montagu. 172 ANCEIDJ:. municate a memoir on the subject to the meeting of the British Association at Oxford, in 1832 ; — a translation of which, with additions, containing the description of some supposed new species of Praniza, was published in the " Annales des Sciences Naturelles." Other supposed species of the t\vo sexes of this genus were published by other authors, namely, Praniza branchialis, of Otto (in " Nova Acta ' of Bonn, vol. xiv.) ; Praniza ven- tricosa, plumosa, and mesosoma, of Risso (" Hist. Nat. Eur. Merid." vol. v.) ; Praniza Reinhardi, of Kroyer (" Gronlands Amfipoder"); Anceus rapax, of Milne Ed- wards (" Hist. Nat. Crust." vol. iii.) ; Anceus vorax, of Lucas ("Annales Soc. Ent. France," 1849); Praniza mauritanica, of Lucas (" Op. Cit.") ; and Praniza obesa, of Lucas (" Op. Cit." and " Hist. Nat. Alger," tome i.). Whilst establishing the genera Gnathia and Praniza for the two sexes of this genus, Dr. Leach had the tact to perceive the possibility of their being sexes of one and the same species, observing (" Edin. Encyc." vii. p. 402) that " Mr. Leach supposes that Oniscus cceruleatus, of Montagu, is the female of this animal ' (Gnathia termi- toides, or maxillaris, Mont.). Hence possibly the reason why Dr. Leach did not introduce his MS. genus Praniza into any of his works ; indeed, he omitted Gnathia in his celebrated memoir published in the " Transactions of the Linnean Society," vol. xi. 1815. In November, 1855, M. Hesse communicated a me- moir to the Academie des Sciences, of Paris,* in which he announced the startling fact that Praniza was but the larva state of Anceus, and that, by a true metamorphosis, Praniza was transformed into Anceus. In the beginning of the following year, 1856, our h Comptes rendus, Nov. 1855, March 1858. Ann. des Sci. Nat. 1858, t. ix. p. 89. ANCEUS. 17' friend, A. H. Haliclay, Esq., communicated to us spe- cimens both of Anceus and Praniza, which he had first taken in 184-7, on the shores of Strangford Lough, in the North of Ireland, in some numbers, and in equal proportions, in the summer, although in the month of February the Praniza were much less abundant than the Ancei. Mr. Haliday's specimens were taken in small cavities in the surface of the clay, under stones, some- times singly, oftener two, and even three and four in each hole; the smaller green ones were few in com- parison. The new-born young of the Praniza have all the characteristic form of the parent, but the posterior thoracic segments not so completely confounded to- gether.* Referring to M. Hesse's memoir, Mr. Haliday ob- served in his communication to us, that " notwithstand- ing their constant association, and the fact that the Anceus is always of pretty uniform size, and Praniza varies from about the same down to the smallest size, I should never have guessed that the latter was the larva of the former ; and yet I do not understand how to com- bine it with my positive observation of Praniza producing young — the very eyes of which (before birth) were visible through the transparent integuments of the parent/' We are able fully to confirm this statement, as some of Mr. Haliday's specimens of the Pranizce still exhibit the mass of eggs within the incubatory pouch, and from others the minute young have escaped in the spirit in which they are preserved. Mr. A. White, in his "Popular History of British Crustacea," 1857, still further confused the matter by observing that " there is some likelihood that Anceus may prove to be one of the stages of Praniza" ' Annals Nat. Hist. 1848, vol. i. p. 65. 174 ANCEULE. In 1858, Mr. Spence Bate communicated a memoir "on Praniza and Anceus, and their Affinity to each other/' in the " Annals of Natural History," 3 ser. vol. ii. pi. 6 and 7, in which, after a careful description of the structure of the two, Anceus and Praniza, and a review of the statements of previous writers, and especially of the memoir of M. Hesse, he arrived at these conclu- sions : — 1. That (upon M. Hesse's observation of Anceus pro- ducing young) Anceus is an adult animal. 2. That (upon his own observation of Praniza pro- ducing young) Praniza is an adult animal. 3. That Praniza, consequently, cannot be developed into Anceus. 4. That Anceus is a distinct genus from Praniza. 5. That the males of both genera have yet to be dis- covered. In 1861, M. Van Beneden, in his " Recherches sur la Faune littorale de Belgique, Crustaces," published a de- tailed description, with figures, of the Oniscus (Praniza) marinus, of Slabber, as the " etat larvaire," and of the Anceus as the " etat adulte ' of the same animal, pre- ceded by a history of the genus, and of the observations of Messieurs Hesse and Spence Bate, together with a supplemental note from the former to the objections of the latter : — " Si vous prenez des Pranizes d'une certaine dimen- sion, c'est-a-dire, pres de 1'epoque de leur transforma- tion, vous n'avez plus, au bout de quelques jours, des Pranizes mais des Ancees des deux sexes — quelques jours avant la transformation des Pranizes femelles en Ancees les ceufs qui preexistent s'apercoivent a travers la peau, et si M. Bate avait vu la suite de cette operation, il eut constate que sa Pranize etait devenue Ancee." ANCEUS. 175 In 1864, M. Hesse published his detailed " Memoire sur les Pranizes et les Ancees," 4to, Paris, with a vast amount of supplemental materials, from which he de- duced the following results : — 1. That Praniza is only a " phase de la metamorphose de la larve en Ancee." 2. That at the end of the larval state, in which sexual differences are not perceivable, these Crustacea are transformed into males and females. 3. That the male and female are completely distinct in form, and that the young state, or Praniza form, is so unlike that of the two sexes, that it may be mistaken for a different species. 4. That the female of Anceus had hitherto been totally unknown . 5. That during their larva, or Praniza form, they are parasitic on fishes, with a mouth fitted for sucking blood, and that after quitting the fishes and assuming the Anceus form, they live " a terre ' with a greatly modified form of the mouth, furnished with formidable mandibles. 6. That the Anceus form is that of their final meta- morphosis. In contrasting these results with the plates which accompany M. Hesse's memoir, we cannot but express our conviction that his conclusions are far from being borne out by his own recorded observations. If the student will but turn to M. Hesse's elaborate memoir, we think that we shall be able even thence to demonstrate the correctness of our own conclusions on these anomalous animals. In plate 1, the figures 9 and 11 nearly correspond in the natural size of the objects, but materially differ in form ; whereas all the larvae in fig. 30 correspond only with fig. 1 1 . This latter cir- cumstance probably may be only the result of the artist's 176 ANCEID2E. speed. Now we contend, and our own observations con- vince us, that fig. 10 is the larval stage of the male, and that fig. 1 1 is a similarly advanced condition, or the larval stage of the female. At the period when the larvae quit the ovigerous pouch of the parent, the simi- larity of the two sexes, it is true, is very close, and not readily distinguishable ; but even at this early period the transparent membranes enveloping the terminal seg- ments of the pereion, seen in the woodcut in page 177, indicates a form more nearly approaching to that of the adult female (or Praniza form of Anceus), than to that of the male or true Anceus. We have examined great numbers of the larvae just as they are ready to quit the ovi-pouch, and think that we could determine a sexual distinction, but we hesitate to pronounce this with certainty, because it appeared to us that both sexes were never developed in the same DEVELOPMENT OP ANCEUS. ANCEUS. 177 ovi-pouch : the young of one animal appearing to be all males, those of another being all females, so that the variation may have been the result of an older or younger stage of development. But, however great the similarity may be between the two sexes at the time of their first leaving the ovi-pouch of the parent, they very soon exhibit a distinguishable variation, as seen in the woodcut on the preceding page, in which fig. 1 (of which IA is an enlarged figure, seen laterally) represents the male larva. That of the female (figs. 2 and £A, seen laterally) has the three posterior segments of the pereion losing their crustaceous and seg- mental character, and putting on that of a membranous condition, and becoming fused together into one long segment. That of the male, as shown in fig. 1, of which IA is an enlarged representation (seen laterally), has the segments well defined and crustaceous, but the central, that is the third (though homologically the fifth), seg- ment of the pereion, considerably increased in length, with the coxae partially fused with the segment. Viewed laterally, this segment is dorsally elevated above those DEVELOPMENT OF ANCEUS. Fig. A. Young of Anceus Edwardii (p. 201). Fig. B. Eggs, Fig. c. Young of Anceus Maxillaris (pp. 176 and 192). VOL. II. N 178 ANCEHLE. posterior to it. That we have not been misled into accepting as parallel stages, conditions which are only successive changes, as is stated by M. Hesse to be the case, we are assured, from the circumstance that we have seen, and have in our possession, specimens of the female from the smallest to the largest size ; and similar ones of the male also, beginning, in each case, with e / DEVELOPMENT OF ANCEUS. This cut represents an animal, with its details, which agrees entirely with Montagu's figure of Praniza cceruleata, and which, notwithstanding its large size, we presume must now be regarded as the fully developed larval form of the female. (Praniza fuscata of Johnston, Oniscus marinus of Slabber, Praniza cceruleata of Costa. Praniza inaculata of Westwood, Praniza mau- ritanica of Lucas, and Praniza Reinhardi of Kroyer, judging from the figures given by these various authors, are animals in their larval condition, whereas Praniza obesa of Lucas decidedly represents an adult ovigerous female.) In the details given above are representations taken in different points of view of the maxillipod (g}, showing the varied positions of the ser- rated portion ; tbe mandibles also (d) are much weaker than those organs are represented either by Mr. Spence Bate (Annals N. H. s. 3, vol. ii. pi. 6), or by M. Hesse. ANCEUS. 1 79 animals scarcely a twentieth of an inch in length up to nearly their full growth. In the young or larval stage, the oral organs are similar in both sexes. In fact the cephalon is much alike in both, being subtriangular ; the eyes lateral, placed at the posterior angle of the cephalon, being somewhat larger in the male than in the female. The superior antennae are shorter than the inferior. The mandibles are an- teriorly produced, and developed into sharp-pointed instruments, with the inner margins acutely serrated, the serrations being directed posteriorly. The maxillae are styliform and sharp ; the inner margin of the first pair is slightly serrated. The maxillipods are four- jointed, and each joint supports a strong styliform spine, and the whole of the oral appendages combine together with a sharp process at the apex of the anterior lip, to form a strong lanceolate organ, with which the animal probably cuts its way through the skin of those fish on which it preys. Posterior to these appendages, near the inferior and outer angle, stands, what we consider to be, the homo- logue of one of the pairs of gnathopoda. From analogy with Tanais, &c., in which the first segment of the body is fused with the head, we should infer that it is the first segment of the body in Anceus which is fused with the head, whence the pair of appen- dages in question would represent the anterior pair of legs (or first pair of gnathopoda), but in Tanais, &c., the second segment of the body is distinct, and bears a pair of legs, whilst in Anceus there is no trace either of this second segment or second pair of legs, unless we suppose the hind part of the head and the pair of appen- dages in question to be the representatives of such second segment and second pair of legs (in which case N 2 180 ANCEID.E. there would be no trace of the anterior pair of legs). In the young stages, this pair of appendages is long, narrow, articulated, with a strong hook at the tip ; but in the adult state they become more or less dilated and shortened in form, varying in the different species. The character of the mouth does not appear to vary until the animal has arrived at its adult stage. We have not yet observed, neither has M. Hesse shown, the way in which, and the period when, the male assumes the large, projecting mandibles. We assume it to be at the last stage between the young animal and the adult, and that these organs are produced at a single moult ; though this is not in accordance with our experience of the general development of this class of animals ; but, certainly, the adult stage is one of a retrograde character, a circumstance that may account for its departure from the usual or normal plan. M. Hesse, in the 27th figure of his first plate, gives a figure of a young animal in the act of moulting. He describes it as a female, " represented at the moment when it undergoes its transformation, and while it is yet enclosed within the skin of Praniza that it is about to quit." This, from our point of view, is merely the development of a younger female into an older one. We have in our collection a very similar specimen ; it is that of a male, but we cannot perceive in the enclosed animal the large mandibles characteristic of the male adult Anceus. We also possess small specimens of the males, not more than two-thirds of the length and half the breadth of the full-grown individuals of this sex, and in which not only are the mandibles scarcely more than one-fourth of the size of those of the latter,* * See woodcut in page 190 : d representing one of the mandibles of the full-grown male, and d d that of the smaller individual. ANCEUS. 181 but the three posterior segments of the body are almost as compactly soldered into a mass as in the females, whilst the two large plates covering the mouth are fully developed. These small males must, we should presume, be subject to another moulting before arriving at the fully developed state of the male sex, unless, indeed, they are slightly developed specimens, such as are known to occur in most cornuted species of animals. The female is said to be parasitic in the young state, and to live in crevices of the rocks when full grown. We believe that this is the case also with the male, and that both males and females change their oral organs with the final or adult moulting. The following remarks which we make on the habits and structure of these animals are so much at variance with the common notions concerning crusta- ceous animals, so high in the class as those of this genus, that we think it but just to ourselves to say, that we have only arrived at them after close and numerous dissections, and a long consideration of the subject. The females live parasitically on fish, burying their heads almost to the eyes ; and we repeat that we believe, that up to the same period the male does also ; but with the adult moult the female quits the parasitic life for a new kind of existence. With the adult moult the male gets rid of the lanceolate oral appendages, and large, pro- jecting mandibles are developed. We have some reason to believe that the production of the great prehensile mandibles of the male may be produced after the animal has put on the adult form, since we have several speci- mens in which these appendages are membranous, and have not yet acquired their distinctive form. It may be, however, that our specimens represent those which, by 182 ANCEID^. some accident, have lost the mandibles, which are now undergoing reproduction. The oral appendages of the female also undergo a great change. As in the male, the lanceolate organs of the mouth are lost ; but, unlike the male, they are replaced by no other appendages. Dissection shows us that they have neither mandibles nor the anterior pair of maxillae. The only appendages which the female adult Anceus has upon the oral surface of the cephalon, are the maxillipods and a pair of gnathopoda, and even these are so depreciated in character as to become rudimentary rather than nor- mal appendages. The maxillae consist of four gradually diminishing joints, supported on a broad base that has the antero-median angle produced to a blunt point. The gnathopods are reduced to two or three joints, at the base of which, on the internal surface, is a broad, exqui- sitely thin, membranous scale.* Still more remarkable, beneath these appendages there appears to be neither mouth, stomach, nor alimentary canal. The immediate assumption of every carcinologist will be that we may have mistaken exuvia, or cast skin, for the animal. With the exuviae all the appendages, together with the stomach and alimentary canal, are thrown off. * Tliis delicate membrane is unnoticed by Hesse and other previous writers. It occurs only in the adult females, and is perfectly identical in its character with the membrane forming the outer cover of the ovigerous sac. If we suppose the large outer pair of appendages of the mouth of the female to represent the second pair of legs or gnathopoda, we at once arrive at the conclusion that this membrane is portion of the ovarian sac, which normally exists in this position (see figure of Paranthura), and, indeed, in the females of the Irish species it seemed to us, on dissection of several specimens, to be actually continuous with the membrane within the first pair of true legs, and to form, in fact, a jugular opening of the pouch, whence we extracted several of the young, the antennae of one of which was actually inserted between this pair of supposed gnathopods of the female. See the upper right hand figure in page 190. ANCEUS. 183 But we have not run the risk of such imputation, having carefully examined the structure of the female before the ova were developed, while they were in the ovisac, and after the presence of embryos in the ovi-pouch ; we therefore think it possible that exceptions to a common law may exist in this as well as in other things. The ovi-pouch of this genus appears not formed by a series of fine scales attached to the coxae, as in the Amphipoda, but by a thin membrane, that is itself the wall of the ventral surface of the animal, which splits into scales when the embryo is ready to take its departure. M. Hesse states the period of incubation to be from twenty to twenty-five days, and sometimes less, and he believes that impregnation takes place prior to the last or adult moult of the animal. This is contrary to our anticipation, and, indeed, contrary to the common law of nature. We have certainly dissected adult animals that have not had the trace of ova. We therefore believe that immediately after the animal has undergone the adult moulting, it ceases from its gormandizing and com- mences breeding, and that, consequently, impregnation takes place immediately after the moult. Observers must have noticed that in the younger stage — that is, until the animal ceased to have a digestive ap- paratus— the animal, by feeding, distends the posterior portion of the pereion to a considerable extent, whence M. Hesse says that " sometimes they are so gorged with blood that they become as distended as if they were full of eggs." It must strike the physiologist as a remarkable circum- stance, that the part which becomes distended by feeding is not the stomach, which in Crustacea exists in the cephalon, but that part which afterwards becomes the reservoir of the future progeny. 184 ANCEID7E. In the earlier period of its parasitic life, the female takes a green colour, which at a later stage deepens into a bright blue. We speak of the common species round our coast, to which Montagu gave the specific name of cceruleata. M. Hesse has figured one of a brilliant red ; we have never seen such, but it is not improbable that some species may change in their colour, which most pro- bably varies with the condition of the food, for we have taken them white, grey, green, blue, and brown. An examination of the material confined within this portion of the pereion shows it to consist of oil and fat globules, and we have been able to determine that it is intimately associated with the nourishment of the animal, since by keeping them without food the coloured mass decreases in size. It is such an animal that Mr. Spence Bate figured in his paper " on Praniza and Anceus" " Annals Nat. Hist." for Sept. 1858, where he observes, " After a few days the blue mass, which first appeared to fill and distend the large segment of the pereion, gra- dually diminished, apparently deteriorating. It recedes first from the margin; in so doing it displays a series of layers, placed one before the other, lying across the animal. There were indications of these layers being divided by cross sections. The relation that this co- loured mass holds to that of the ova which, at a later period, take its place, we know not ; but we are inclined to believe that it is a reservoir of fat on which the animal is supported during the period of incubation. We have not been fortunate enough to obtain em- bryonic forms of the larvae so young as those figured by M. Hesse (plate 1, figs. 5, 6, and 7), which, by their single central eye and general form, resemble the larvae of some entomostracous species of Crustacea, a form that Dr. Fritz Miiller contends, with some apparent show ANCEUS. 185 of correctness, is the earliest stage in all crustaceous life. The ova are proportionately very large, and the parent retains the young after it has quitted the egg, until the young animal is scarcely less than half the length of the parent. M. Hesse has figured a speci- men, in which he has represented all the larvae placed within the ovi-pouch in a uniform manner, the head of each being directed towards the centre of the pouch ; this is not in accordance with our observations, as, of the number of specimens that we have seen carrying young, we have found all with the young creatures variously placed, some with the head, others with the tail, directed forwards or across. When the young quit the care of the parent, nothing but a thin, transparent skin remains, and the parent probably dies. The male differs from the female by the presence of a remarkable pair of mandibles directed forwards ; fierce and terrible organs of prehension they must be, but they have always struck us as being organs that must be valueless in assisting the animal in feeding. After we had observed the structure of the oral organs of the female, we directed our attention to those of the male. In A. maocillaris,* on the under surface of the head, exists a pair of large two-jointed plates, the basal being sub- triangular and large, the other small and apical. From its position and structure we consider this as the representative of the hooked appendage in the young animal, consequently the homologue of one of the pairs of gnathopoda ; beneath this lies a pair of foot-jaws, in form very closely resembling those of the adult female. On removing these, we arrive at a crustaceous surface, with a minute and apparently imperforated tubercle in * See the various details of the underside of the head and its organs represented in p. 190. 186 the middle. That the male animal should be without a mouth and digestive apparatus, we certainly were not prepared to find, since the presence of the mandibles, though unusually placed, induced us to expect the existence of a prima via as much as we had deduced its absence, from finding those organs wanting in the female. The large lateral lobes of the cephalon are filled with muscles, which hold and move the powerful mandibles that can only exist as organs with which to grasp the female. From the facts which have now been observed, assisted by the elaborate labours of M. Hesse, we have arrived at the following conclusions : — 1st. That Anceus of Risso and other authors, with a large head and porrected mandibles, is the fully de- veloped male state of this genus. 2nd. That Praniza of Leach and other authors, with a small head, is the female state, either in an unimpregnated or gravid state, 3rd. That the larva form of the animals of both sexes, although closely resembling each other, may be distin- guished at a very early stage of their growth, even if not immediately after birth. We hope that the conclusions at which we have thus arrived will be tested by close observers. There are also some points of interest in the internal structure of these animals that have yet to be worked out. ANCEUS MAXILLARIS. TSOPODA. ABERRANT[A. 187 ANCEID^E. d ANCEUS MAXILLARIS. Specific character. Male with the cephalon broader than long, dorsally depressed, especially in the middle and anterior part, and finely granulated on each side within the eyes ; fore margin transverse, with a prominent tubercle within the mandibles, the centre itself having a much less prominent conical tubercle. Mandibles about two-thirds of the length of the cephalon, with a strong notch on the outer edge, and about ten denticulations on the inner edge, the apex forming a sharp tooth. The second pair of gnathopoda with the three or four basal segments soldered into a large flattened semioval plate, strongly ciliated on the inner margin. Male exserted organ very long and thin. Legs very finely serrated on the middle joints. Female, with the second pair of gnathopoda strong, two-jointed, basal joint angulated ; first pair of gnathopoda like those of the male. Length \ of an inch. MONTAGU, Trana. Linn. Soc. vii. p. 65, t. 6, f. 2. LEACH, Enc. Brit. Suppl. Encycl. Method. Crust, pi. 336, fig. 25. LAMARCK, Anim. sans. Vert. v. p. 168. DESMAREST, Cons. Crust, p. 283, (Male) Cancer maxillaris. Gnatliia maxillaris. Anceus maxillaris. 188 ANCEID.E. (Male) Onathia termitoides. Anceus rapax 1 Anceus scarites? P . (Female) Oniscus cceruleatus var, Praniza Montagui. Praniza obesa ? (Immat.fem.) Oniscus cceruleatus. Praniza cceruleata. Onatkia termitoides. t. 46, f. 6. WESTWOOD, Annales Sci. Nat. xxvii. p. 329. MILNE EDWARDS, Crust, iii. p. 197. WHITE, B. M. Cat. Brit. Crust, p. 74. Pop. Hist. Brit. Crust, p. 243, pi. xiii. f. 5. SPENCE BATE, Ann. Nat. Hist. ser. 3, vol. 2, pi. 7, f. 1, and details. LEACH, Edin. Encyc. vii. p. 402. MILNE EDWARDS, Crust, iii. p. 196, t. 33, f. 12. Regne Anim. Ed. Crochard Crust, pi. 62, fig. 3. HESSE, Mem. Etrang. Acad. Sci. t. xviii. p. 57, pi. 3, fig. 15, 16. , MONTAGU, Trans. Linn. Soc. xi. p. 16. WESTWOOD, in Annales des Sci. Nat. vol. xxvii. p. 327. LUCAS, in Ann. Ent. Soc. France, 1849, p. 465, pi. 15, f. 3. MONTAGU, Trans. Linn. Soc. xi. p. 15, t. 4. f. 2. (Copied Enc. Meth. Crust, pi. 339, f. 28, with the in- correct name Oniscus (Ccelino, Leach) thoracicus, Mont.). DESMAREST, Cons. Crust, p. 284, t. 46, f. 8. WESTWOOD, in Ann. Sci. Nat. xxvii. p. 326, t. 6, f. 5. MILNE EDWARDS, Crust, iii. p. 194, t. 33, f. 10. WHITE, B. M. Cat. Brit. Crust, p. 74. Pop. Hist. Brit. Crust, p. 240, pi. xiii. f. 4. SPENCE BATE, Ann. Nat. Hist. ser. 3, vol. 2, pi. vi. f. 4. (Feni.?) LEACH, Edinb. Euc. vii. p. 402. THE male of this species, figured in the preceding page, is distinguished by the large size of the head, which, together with the very prominent mandibular appendages, give£ the animal a fierce aspect. The head is nearly square, and about the size of the three anterior segments of the body conjoined ; it is slightly broader across the middle, the eyes occupying the anterior lateral margins, in front of which the head on each side is somewhat squarely truncated, the antennae being affixed in front of ANCEUS MAXILLAR1S. 189 the antero-lateral angles thus formed : within the place of insertion of the antennae on each side, the anterior margin of the head is somewhat porrected, and trans- verse, with a prominent tubercle on each side, the space between these two tubercles being emarginate, with a small prominence in the middle. The dorsal surface, of the anterior half of the head, is depressed, an evident channel running from the middle of the fore margin to the centre of the head, where it meets with a small posterior longitudinal carina, behind which is a very short transverse ridge (which may indicate the point of union of the two segments of the pereion soldered to the head). On either side, arising from the inner margin of the eyes, is a short slightly impressed fossa, the surface of which is more or less strongly granulated. The superior antennae are about the length of the mandibles, slender, with two equal-sized basal joints, a longer third joint and a five- jointed flagellum reaching to the tip of the fourth joint of the lower antennae, which latter are nearly as long as the head and rather thicker than the upper pair, with two short basal joints ; a third and fourth joint, more robust and of nearly equal length (equalling that of the third joint of the upper pair), and a short flagellum of six articuli. The mandibles are of large size, being about two-thirds of the length of the head. They are nearly flat above, of a somewhat elongate-triangular form, with a prominent tooth in the middle of the outer edge, the apex prolonged into a curved tooth, and the inner margin armed with nine or ten small obtuse teeth ; the inferior sur- face of the head is protected by a pair of large flat valve- like organs, each about half the size of the head itself (and which might be supposed to represent the second pair of gnathopoda (i)9 corresponding with the second pair of feet of the typical Isopods, but lettered g in the figures in 190 ANCEID.E. the following cut). Each valve is somewhat of an oval form, the outer edge nearly straight, fitting the somewhat triangular deep impression on the underside of the head : the inner margin of each valve is strongly ciliated, and 9 Jr. along the middle of the disc are three thickened circular calcareous masses (apparently representing the ossified centres of the three joints, of which this portion is pro- bably composed). The somewhat pointed apex of each of these valves is furnished with a minute joint, setose at its tip. These valves are attached near the posterior lateral angles of the head ; they are ordinarily shut together, their inner margins overlapping each other, so as to form an under covering of the head. Within them arises a much smaller and more delicate pair of appendages (possibly homologous with the first pair of gnathopoda) (h but marked / in the above figure), composed of a somewhat square basal piece, with its ANCEUS MAXILLARIS. 191 inner apical angle produced into a slender elongated process, followed "by four joints attached together obliquely, with a strong coating of bristles directed obliquely backwards along their outer margin. The first and second free segments of the body are about the same width as the head, short, transverse, with the sides rather rounded and dilated ; the three following segments are somewhat narrowed, longer, much more irregular, and less distinctly separated from each other than the anterior segments, and with the lateral margins rounded and directed somewhat backwards. There is a small short transverse piece in the middle between the last segment of the body (pereion) and the first segment of the tail (pleon). The pleon is about equal to two- thirds of the length of the head, and consists of five transverse seg- ments, followed by a triangular central terminal plate, each segment being furnished on each side beneath with two pairs of very delicate, strongly ciliated, branchial scales. The tail (pleon) is not half the width of the hind part of the body. The legs are of moderate length and rather robust, with some small tubercles on the inner margin of the middle joints. The female, in its fully developed gravid state, as represented in the following page, is a little longer than the male, and has the body greatly swollen with eggs, or young ; the head, anterior segments of the body, and tail being small, and marked all over with minute dark points. The head is subtriangular, without any appearance of the immense jaws of the male (of which, indeed, we have not found the slightest vestige). The upper antennae are small, and consist of a short basal joint, followed by two nearly equal longer joints, and a short and slender ter- minal flagellum. The lower antennae are much stronger and longer than the upper, and consist of two strong 192 ANCEID.'E, basal joints followed by two longer ones, the fourth being somewhat larger than the third, and followed by a slender setose six-jointed flagellum. The inferior surface is covered by two pairs of appendages (the gnathopoda), the outer of which appears to consist of only two distinct joints, although traces may be observed of their being composed of several joints closely soldered together (fig. g. $). The first of these joints is rather wide, flat- tened, and considerably angulated beyond the middle, the basal half being more curved and the distal half nearly straight ; this is followed by an elongate-ovate joint* setose at its extremity ; and in certain positions we perceived an indication of a very minute apical articu- lation amongst the terminal setas. Within this pair of appendages lies a pair of extremely delicate, flat mem- branes, which we have above regarded as the anterior of the incubatory scales, and within these are a second pair of appendages (first pair of gnathopoda), similar in form ANCEUS MAXILLARIS. 193 and articulation to those of the male. We have found no other trace of mouth organs in these developed females. The two succeeding segments of the body are quite dis- tinct, very short, and rounded at the sides, but the three terminal segments are consolidated into a large oval mass covered with delicate membranes, through which the eggs and young are plainly visible ; the black eyes of the latter giving to this part of the body a speckled appearance, and showing at the same time that the arrangement of the young within the incubatory pouch is completely irregular ; and we have never seen the sym- metrical arrangement of the larvae as figured by M. Hesse in the gravid female. The tail (pleon) and its appen- dages resemble those of the male, and the legs do not exhibit any more marked differences beyond being some- what more slender. One of the young extracted from the pouch of the parent, and which attains to more than a third the length of the adult animal before it quits the ovi sac, is represented at the left hand side of the above engraving. The state of these animals previous to arriving at com- plete maturity offers several circumstances sufficiently remarkable to account for the larger sized larvae (if we may so term them; having been mistaken for fully developed females. It is this state which was first described by Slabber and Montagu, and also by Mr. Spence Bate, who confounded it with the adult animal, in the "Annals of Natural History' for September, 1858. The large mass formed by the consolidation of the three posterior segments of the body is of a very elongated oval shape, and in the individuals described by Montagu was of a fine blue colour ; whence the specific name which he applied to it. It varies, however, not only in different individuals, but also in different states of the VOL. II. O 194 ANCEDXaS. respective animals. We have received them of a bright grass-green from Mr. Loughrin, of Polperro : blue from the crevices in the slate in Plymouth Sound, and have dredged them of an ash-grey, as well as transparent and dirty white, in five or six fathoms of water in the same locality.* " The varieties of colour," observes Mr. Spence Bate, "appear to be dependent upon the pro- gress made in the advancement towards spawning, or in some way connected with the development of the ova. When the animal is blue, I have observed a double line of ova traversing the length of the enlarged segment. This I presume to be the ovary, or oviduct, previous to the escape of the ova into the incubatory pouch, which they ultimately fill to the apparent annihilation of the other contents of this part of the animal. I have watched specimens in a glass, and have perceived, after a few days, that the blue mass, which at first appeared to fill and distend the large segment of the pereion, gradually diminished. It recedes first from the margin ; in so doing it displays a series of layers placed one before the other lying across the animal. There were indications also of these layers being divided by cross sections. The ova fill the pouch first, as seen in fig. 6, and ultimately, as shown in fig. 8 (copied in p. 177), where the embryo has considerably advanced towards completion. The blue appearance is now changed to brown — a circumstance that is due to the reddish pigment cells which mark the pereion of the young animal." Thus, at a period before the animal has acquired its final condition, in which the suctorial structure of the mouth is entirely lost, we find the ova to be present, but probably impregnation does not take place until the assumption of the final state. r M. Hesse figures them also of a lemon colour, blood red, and sea-green. ANCEUS MAXILLARIS. ]95 We have no hesitation in referring the animals above described to the Cancer maxillaris of Montagu. His description is indeed very concise, and his figure very rude, but an examination of the specimens preserved in the British Museum Collection leave no doubt on this point, all the males having the notch on the outer edge of the mandibles, forming a small tooth. Our specimens, moreover, have been found in con- siderable numbers along the Devonshire coast, in Mon- tagu's localities. We are also able to state that Mr. Montagu was acquainted with the fully developed female, from an examination of his series of original drawings now in the hands of Mr. Parfitt of Exeter ; whence we further learn that Montagu's variety of his Oniscus cceruleatus, having the body white, with the head, pereion, and pleon maculated with yellow (which Montagu shrewdly suggested might possibly be a sexual variation), is a fully developed female. The name, there- fore, of Praniza Montagui, which Professor Westwood proposed for this variety, must sink into a synonym. Mr. W. P. Cocks found the males in crevices of rocks at extreme low-water mark at Gwyllyn Yase, and in trawl refuse, whilst the Praniza he took most abundantly in the neighbourhood of Falmouth, and a specimen in the British Museum, labelled P. flavus, Bantham, Falmouth, is undoubtedly a female of this species. Montagu only obtained two specimens of his Oniscus caruleatus, which were found adhering to the body of the Father lasher (Coitus scorpius) on the Devonshire coast. The late Mr. W. Thompson's collection also con- tains specimens of the males found amongst dredged matter at Bangor, in Ireland, in the month of August, and also upon Bangor oysters in the month of December. Mr. Norman also communicated to Professor Bell speci- o 2 196 ANCEHXE. inens found on a stone brought up whilst haddock-fishing, and females found upon a shell of Limitella communis. Mr. Robertson has sent us both male and female speci- mens from the Isle of Man, all taken under dead Balani. We were at first disposed to regard our species as identical with the Anceus manticora of M. Hesse's memoir ; but the details which he has given of that species do not agree with those which our specimens present, and which, consequently, induce us to refer the species rather to his Anceus Scarites, pi. iii. fig. 15 ; although we have certainly never seen specimens ex- hibiting the singular marking which he has represented : the large patch in the centre of the three conjoined segments of the body agrees, however, with the males of our species, except that in the latter this patch is only visible on the ventral surface. We believe, also, that our species is identical with the Anceus rapax of Milne Edwards, — as in fact that learned author has suggested, — although in his figure he does not represent the notch on the outer edge of the mandibles. ANCEUS (PRANIZA) FTJSCATA. 197 DOUBTFUL SPECIES. ANCEUS (PRANIZA) FUSCATA. Praniza fitscata. JOHNSTON, in Mag. Nat. Hist. v. p. 520, f. 99. WESTWOOD, in Ann. Sci. Nat. t. 27, pi. vi. f. 26. WHITE, B. M. Cat. Brit, Crust, p. 74. Pop. Hist. Brit. Crust, p. 241. THE late Dr. Johnston indicated, as a distinct species of Praniza, certain individuals evidently in an imma- ture condition, which he had taken on the Berwickshire coast, and which, in the present state of our knowledge of the species of this genus, it is impossible to assign to the real mature representatives. They are described as being two lines long, with the cephalon, two anterior segments of the pereion, pleon, and legs colourless and transparent, the eyes black, the large terminal con- solidated mass of the pereion reddish-brown ; the ce- phalon is pointed, the antennae lateral, four-jointed, the last joint long and divided by many transverse lines; the eyes lateral, large, and compound, like those of insects. The pereion (which Johnston called the ab- domen) is ovate, with a translucent edge and three pairs of legs. The pleon is straight, six-jointed, the joints equal, distinct, armed on the underside with four rows of compressed fins, ciliated on the margins, and the ultimate joint terminated besides with four similar appendages, and a triangular process (the telson) between them. The large pereion is in some specimens smooth 198 ANCEIM. and even, but in others (one of which had been selected for the figure) it is raised at the top (or anterior part) into two oval bosses, that greatly resemble the elytra of a Meloe, and are beautifully punctured ; the same parts are apparent on the visible surface of both va- rieties, but much smaller in that whose back is smooth. Dr. Johnston suggested this to be a sexual distinction. The following vignette, kindly drawn for us by Miss Annie Wright, represents Balarcadden Bay, Howth, near which place Mr. Haliday obtained his specimens of this genus. BALARCADDEN BAY, HOWTH. ANCEUS (PKANIZA) MACULATA. 100 ANCEUS (PRANIZA) MACULATA. Praniza maculata, WESTWOOD, in Ann. Sci. Nat. xxvii.p. 326, t. 6, f. 4-25. GUEKIN MEN., Icon. R. An. Crust, pi. 27, f. 10, a, b. MILNE EDWARDS, Crust, iii. p. 195. WHITE, B. M. Cat. Brit. Crust, p. 74. UNDER the name of P. maculata, Professor Westwoocl described, in his memoir on Praniza above referred to, certain immature individuals belonging to the group, which he had received in spirits from the Rev. F. W. Hope, in company with various small parasitic Crustacea, collected on the coast of Shetland. These three spe- cimens varied from one and a quarter to two lines in length, and, with the exception of the large consolidated hind pereionic mass, which was of a dark reddish -brown, were of a brownish-white colour, with a row of brown spots on each side of the five segments of the pleon, and with various small dots of the same colour scattered over the terminal segment. The largest and smallest individual agreed together in having the hind portion of the pereion of a texture identical with the rest of the body, and distinctly divided into three segments, of which the first was larger than the two others, whereas the third individual, intermediate in its size, had this portion of the body consolidated into a solid mass, resembling hardened wax covered with a fine mem- brane. The former individuals were considered to be males, and the latter a female ; a suggestion which seems confirmed by what has been advanced in a pre- 200 ANCEDXE. vious page. That all of them were in an immature condition is evident from the careful analysis of the mouth, published in the memoir in which their descrip- tion appeared, and which, together with the relative structures of the cephalon and pereion, and other cha- racters, led Professor Westwood to consider that this genus, and several others equally abnormal, ought to form a distinct division, intermediate between the Amphipoda and Isopoda (such, indeed, as Dana has formed under the name of Anisopodd), displacing the Lsemodipoda of Latreille (Caprellidae), from the osculant situation which they had held in the classification pro- posed by that author. ANCEUS EDWARDI1. ISOPODA. ABEREAXTIA. 201 ANCEID^E. ANCEUS EDWAEDII. Specific character. Female with the three posterior segments of the body forming an elongate -ovate mass. Outer gnathopod minute, four-jointed, inner gnathopod very large, five-jointed, the basal joint not produced into a linear appendage at its inner angle, terminal joints densely ciliated on the outside. Length, one-sixth of an inch. Praniza Edwardii. SPENCE BATE, in Annals Nat. Hist. ser. 3, vol. f f, pi. vi. figs. 1, 2, and details. UNDER this name have been described certain female individuals belonging to this genus, which had cer- tainly arrived at the adult state, as proved, not only by the existence of fully developed larvae within the incubatory pouch, but also by the structure of the mouth organs, which had entirely lost the suctorial form of the immature condition. These females are of a much narrower and more elongate form than the fully developed females of either of the other species described in this work. It is, in fact, owing to these animals being in the fully developed state that they possess " the more continuous and less graceful outline from the anterior part of the head to the posterior part of the pereion," which the author indicated as distinguishing these animals from the full-grown larvae of Praniza carulcata. 202 ANCEID^. He also notices " the shortness of the pleon, and the smallness and more equal size of the pereiopoda." The three organs on the right-hand side of the above wood- cut represent first, to the left, the four-jointed outer foot- jaw, of comparatively very small size, the basal joint being large and curved, and the apical one very minute. The middle, scale-like, exarticulate piece clearly repre- sents the scale, which is the homotype of those belonging to the incubatory pouch ; and the large five-joint organ to the right is one of the inner pair of the foot-jaws which, in the female of A. maxillaris, is comparatively very minute, and which we have failed to discover in the female of A. Halidaii. The organ represented on the left side of our woodcut is the outer foot-jaw seen in a different position, in which the minute apical joint is not visible. These specimens were forwarded from Banff by Mr. Edward, in whose honour they were specifically named. One of them was charged with young, and a figure of one of the larvae extracted from the incubatory pouch is represented in the left- hand figure of the woodcut upon p. 177. " It is a remarkable fact," observes the author in introductory remarks on the genus, " that in the young the organs generally bear a closer resemblance to those of P. c&ru- leata than to those of their own parent species." We are now able to account for this remarkable fact, from having learned that P. cceruleata, which we then con- sidered as a distinct species in a fully developed con- dition, is only a full-grown larva of the preceding species. Our knowledge of the present species must of course be considered as imperfect until its legitimate male is discovered. ANCEUS HALIDAII. I SO POD A. ABERRAXTIA. ANCEID^E. ANCEUS HALIDAII. Specific character. Male, with the cephalon nearly square, the lateral anterior angles truncated for the insertion of the antennae, middle of the fore margin produced into three broad divisions, of which the central is slightly porrected ; margin finely serrated ; antero-dorsal surface of cephalon very broadly concave ; mandibles small, scarcely half the length of the cephalon, entire on the outer margin ; second pair of gnathopoda composed of five broad joints. Male exserted organ rather short and thick; pereiopoda with small spines on the terminal joints. Female, with the outer gnathopoda five-jointed, narrower than in the male ; inner gnathopoda wanting ? Length, one quarter of an inch. Anceus formica ? HESSE, Mem. fitrang. Acad. Sci. t. xviii. p. 39, pi. iii. figs. 5, 6, 7. THIS species is at once distinguished from A. maxil- laris by the very different structure and small size of the mandibles and foot-jaws in the males, and by the latter character as well as the (apparent) want of the inner pair of foot-jaws in the females. The head of .-. 204 ANCEIDJl. the male is somewhat quadrate in form, having the anterior margin more prominent than in the preceding species ; the upper surface of the head is more broadly and regularly concave, and the mandibles are scarcely more than one-third of the length of the head ; they are curved, with the tip produced into a sharp tooth, below which the inner margin is armed with about eight small, sharp teeth. When shut, these mandibles project but a small distance beyond the crenated fore margin of the head. The antennae are about the length of the head, the upper ones being shorter and considerably more slender than the lower pair ; the latter pair are composed of two strong basal joints, followed by a third joint, rather longer than the second ; the fourth is still longer, rather thickened at the tip, where it is armed with several setae, and is followed by an eight-jointed nagellum. The upper pair scarcely extends beyond the base of the flagellum of the lower pair. The outer foot-jaws are formed of a large basal joint, somewhat ovate-trun- cate in form, affixed transversely by its base near the posterior angles of the underside of the head ; the re- mainder of the organ consists of four joints, forming a broad, somewhat oval, flattened mass, affixed so as to form an angle on the basal joint; the first of these four joints is small, and furnished with a strong seta on its inner angle, whilst the remaining joints are densely ciliated along the margin. The inner pair of foot-jaws differs considerably from the same organs in A. maxillaris, being formed of a large white, tumid, semi- circular basal joint, having a small lobe at its inner extremity, followed by four joints excessively delicate and thin in their texture, and furnished on the outside with long obliquely deflexed setee. The head is sepa- rated from the first distinct segment of the body by a ANCEUS HAL1DAII. 205 very short transverse ridge, and the two succeeding seg- ments are much shorter than the three posterior, which are irregular in the form of their lateral margins, the posterior angles of each of which is produced into a rounded lobe. The tail (pleon) is composed of six seg- ments, of which the five anterior are furnished on each side with a double scale, the outer division being narrower than the inner, and terminated by a slender point, or short strong seta, whilst the inner division is oval, slightly ciliated at its margins, of a delicate transparent texture, allowing the circulation to be seen within, and which is carried round the organs within the lateral margins, as indicated by the arrows in the accompanying figure ; the tail is terminated by a small triangular joint, furnished at each side with a pair of strongly ciliated, delicate elongate-ovate plates. The legs are more robust than in A. maxillaris, and have the terminal joints armed with several small spines. The female closely resembles that of A. maxillaris, but is at once distinguished by the form of the outer appendages of the mouth (the head of this sex is repre- sented in the upper right-hand figure of the engraving upon page 190). These organs are composed of five joints, of which the basal one is the largest, and is attached near the outer posterior angles of the underside of the head in a transverse direction, the remaining joints forming a somewhat oval flattened mass, of which the first joint is small and transverse, the next larger and semi-ovate, and the terminal joint very minute. We have not been able to discover any trace of the inner pair of foot-jaws. This species was discovered by our friend Mr. Alex- ander H. Haliday, and is referred to in a communication dated October 9, 1847, which was published in the 206 ANCEUXE. " Annals of Natural History " (No. 5 for 1848, vol. i. p. 65), in which he remarks : "I found a species of Praniza, pretty common on the clayey shores of Strang- ford Loch, last week in company with Anceus maxillaris [i.e. the male of A. Halidaii above described]. They were in small cavities on the surface of the clay, under stones, sometimes singly, oftener two, or even three and four in each hole ; the smaller slender green one * were few in comparison. You will find some of the new-born young with them having all the characteristic form of the parent, but the posterior thoracic segments not so completely confounded together." Mr. Haliday furnished us with living specimens of both sexes and all sizes, captured at the end of February, 1856, amongst which, however, the males preponderated in number, the immature females being scarce at that period of the year, whilst in the summer they bore a fair proportion to the adult male, which was abundant enough. On the 14th March following, he observed in a letter to us : " It was only the other day I observed the notice in the ' Comptes rendus ' of the Paris Academy, of Hesse's observations on the identity of Anceus and Praniza. Notwith- standing their constant association, and the fact that the Anceus is always of pretty uniform size, and Pra- niza varies from about the same down to the smallest size, I should never have guessed that the latter was the larva of the former, and yet do not understand how to combine it with my positive observation of Praniza producing young, the very eyes of which (be- fore birth) were visible through the transparent integu- ments of the parent." This Irish species appears at first sight most nearly to approach the Anceus formica of M. Hesse's memoir. Our specimens, however, not only exhibit none of the ANCEUS HAJJDAII. 2Q7 strongly defined coloration which his figures represent, but the outer pair of foot-jaws in the male of that species are formed of a large lunate exarticulate mass. The only other species, A. brivatensis, which M. Hesse describes as belonging to his first section (to which our Irish species seems to be referable), differs in the much broader head and in the strongly angulated sides of the two anterior segments of the body. Moreover, his figure of the underside of the male of A. brivatensis shows the outer foot-jaws as of so small a size as not closing the mouth, and " formee d'une lame large ter- minee a son extremite par un petit appendice ovale et cilie." In this indecision we have thought it more advisable to propose for this Irish species the name of the gen- tleman by whom it was discovered, and by whom so many interesting additions, in different tribes of annulose animals, have been discovered and most satisfactorily investigated. 208 ISOPODA NORMALIA. ISOPODA NORMALIA. THIS group comprises the great majority of the order which are distinguished by the nearly uniform size of the seven segments which compose the pereion, as well as of the seven pairs of legs attached to such segments. The cephalon is always distinct ; the branchial organs are attached to the underside of the segments of the pleon, being closely connected with the pleopoda, and lie upon each other, being sometimes covered by a larger outer pair, in the more normal forms. The Isopoda normalia constitute two principal divi- sions, founded upon the situation inhabited by the animals of which they are composed ; the majority (Aqua- spirantia) residing, either free or in a parasitic condition, upon animals which live in the water, and consequently breathing oxygen from the water in which they live ; whilst those of the other division (Aero-spirantia) reside on the land, generally indeed in deep situations, and breathe the free air by means of series of branchial plates, probably assisted by spiracles with which the branchiae are furnished. ISOPODA . 209 Division— AQUASPIRANTIA. THE animals composing this division are likewise divisible into two tribes, according to the nature of their habits and the situations in which they are conse- quently found, being either 1. Parasitica., parasitic and fixed on other aquatic animals, or, 2. Liberatica, free, and crawling or swimming about in the water. Tribe— PARASITICA. The first of these tribes comprises the species which reside upon other crustaceans and fishes, and which may conveniently be subdivided in the following manner : — 1. Those in which the sexes are greatly dissimilar in form and size, and which are parasitic upon other crus- taceous animals. Family — Bopyridce. 2. Those in which the sexes are similar in general form and size, which are found parasitic upon fishes, and which are divisible into — A. Those which have the base of the antennae concealed beneath the porrected front of the head. Family — Cymothoida (of which no representative has hitherto been recorded as a native of our coasts). B. Those which have the antennas naked or but slightly covered at the base. Family — JEyidte. VOL. II. 210 BOPYRID.K. Fam.— BOPYRID^E. THIS family (corresponding with the section Epicarides of Latreille, and the Isopodes sedentaires of Milne Ed- wards), although but of small extent, as to the number of the species of which it is composed, exhibits some of the most remarkable modifications of structure amongst its different members, whilst the characters of the group render it a very distinct one amongst the families of which the order is composed. So far as hitherto ascer- tained, the species are entirely parasitic upon the bodies of other crustaceous animals, especially those of the shrimp family and hermit crabs ; species also of the genera Galathea, Gebia, Gelasimus, and even of Mysis, have been found to be infested by them. The body, particularly of the female, is in most of the species of a much less firm consistence than in the majority of the order and in their full-grown condition, there is a marvellous difference in the size of the two sexes, the females being very large, ovate, or nearly cir- cular in form, with the segments very indistinct, whilst the males are very diminutive and elongated, with the segments of the body quite distinct.* In both sexes the antennae are very short, and more or less rudimentary, consisting of only two or three joints in the Bopyri, but with a more distinctly articulated flagellum in some of the Phryxi. The mouth is very rudimental, consisting in the female and probably in the * In this respect these insects offer a marked analogy to the family Coccidce amongst hexapod insects. The female Cocci gi'adually lose their locomotive organs and become inert animal masses, capable only of suction and deposi- tion of eggs, with which the body seems entirely filled. BOPYRIP.E. 211 male also of a pair of mandibles deferentiated into a pointed siphon-like organ, the two appendages meeting together in a slight twist, and so strengthening each other as a penetrating organ, which is protected by one or two pairs of broad fleshy scale-like maxillae, of which the first pair is generally bi- or tri-articulate, and the others almost without trace of articulation, and united for the most part to the under surface of the head by a small joint. The legs are very short, having a broad hand strongly hooked at the tip for prehension ; in some of the species the full-grown females lose the greater portion of these limbs. They are furnished with large incubatory plates on the underside of the body : in some species, however, they have the appearance of being recurved, and of covering the upper side of the animal. (See Hesse, Ann. Sci. Nat. ser. 5, t. iii. p. 237, where this, and t. iv. p. 226, where the reverse is stated to be the case.) The tail (pleon) generally forms a distinct portion of the animal, and is composed of a series of short segments, which are often furnished with elongated lamellae, or other analogous appendages, most conspicuous in the female. The male is always very small, and much narrower than the female, with the head and seven segments of the body distinct, and each segment is furnished with a pair of short legs formed like those of the female, but more slender ; the tail (pleon) is also more elongated, with the joints often distinct ; the eyes are also distinct in the males, although only rudimental or wanting in the females. The young of these animals are of an oval form, not unlike that of a wood-louse, having the segments of the tail of a comparatively larger size than in the adult state ; in the typical genera they are furnished with two pairs of antennae, of which the anterior are short, but the posterior P 2 212 BOPYRIIXE. pair are greatly elongated and furnished with very long ter- minal setae, which are used as powerful organs of locomo- tion ; the legs are short, but strong and prehensile, and the tail is furnished beneath, at the sides, with five pairs of flattened, oval, ciliated appendages, those of the sixth or last segment being elongated, and terminated by a pair of slender styles, which are armed at the tips with long- setae. They are very active in this state. Whilst in the character of the head, which projects beyond and above the antennae, and in the form of the last three pairs of legs, there is a close approximation to the larval form of the parasitic Amphipoda forming the group Hyperina. It hence appears that the earliest or larval con- ditions of these parasites is their highest and most advanced stage ; the organs of sense and motion being proportionately larger and better developed at that period of their existence than ever after. It would thus appear as if the nervous energy were then greater, and that the growth of both males and females is but, what Dana calls, a vegetative process, and one that is destructive of cephalization, which decreases in proportion to the growth of the animal. We therefore argue that, of the adult Bopyri, the smaller male ought to be taken as typical of the species rather than the more abnormal female.* The two families proposed by Mr. Milne Edwards, * This principle seems, indeed, capable of extension, since wherever amongst the Articulata an animal exhibits the sexual organs, or those which more especially characterize the sex, in an unusual state of development, the opposite sex is necessarily more decidedly typical of the group to which the species belongs. Thus, among moths, the immensely pectinated antennae, and the more decided shape of the wings of the males, render the females better exponents of the groups to which they respectively belong than the males ; whereas in the genera Orgyia among the moths, Cebrio and Drilus among beetles, Coccus among the Homoptera, in all which, for sexual pur- poses, the wings remain undeveloped, and the body becomes dilated to an enormous size filled with eggs, the opposite necessarily takes place. BOPYRID.E. Bopyriens and loniens, established upon the foliaceous or filiform structure of the appendages of the tail, cannot be maintained, as several genera have been lately dis- covered which are truly Bopyrideous, although furnished with filiform and even clavate caudal appendages. The genera Prosthetes and Athelges, parasites on the tails of hermit crabs (Paguri), are, in respect to the peculiar formation of their pleonic appendages, amongst the most remarkable of crustaceous animals. In lone, these organs are singularly branched, resembling pieces of coral, and the incubatory plates are furnished with long clavate appendages. We bave added the anomalous parasitic genus Liriope to this family (rather than place it near Tanais, as done by Dana), from a consideration of its general character. The entire want of limbs in the female, and the somewhat indistinctly articulated body of the males, with the pleon destitute of lateral terminal appendages, are very characteristic distinctions, separating it from the majority of the family, but, at the same time, removing it still farther from the Tanaides. The genus Crypt othir of Dana appears to us to be founded upon a carelessly examined male of a species of Liriope, as may be at once perceived by comparing Dana's figure of Crypt, minutum with our figure of Liriope pygmtea. The family, at first, comprised only the genus Bopyrus, a separate family having been proposed for lone, but more recent observations have fully proved, as stated above, not only that the two animals are closely united together by the intervention of several genera discovered since the publication of M. Milne Edwards's general work on the Crustacea, such as Kepon, Phryxus, and Aihelges, &c., but that the genera Gyge of Cornalia and Panceri, Dajus of Kroyer, Ledya of Cornalia, and Argeia of Dana must be added to the familv. 214 I SOP ODA . K OP YRID^E. NORM ALIA. Genus— BOPYRUS, LATREILLE. THE male of this genus is very small, narrow, and elongated, resembling an Idotea in its general form, but with only rudimentary antennae, and with the pleon gradually narrowed to the tip and formed of six segments fused together, except at the margin, and apparently destitute of lateral appendages. The body is symme- trical in its shape. The cephalon is distinct, transversely ovate, and fur- nished on the underside with two pairs of antennae, the outer pair of which are composed of four short joints, ter- minated by setae, whilst the inner pair are almost rudi- mental, and composed apparently of only two joints ; the mouth is also almost rudimental, forming a conical point. The seven pairs of legs are of nearly equal size, and of considerable strength and thickness ; they are affixed on the underside of the body, near the lateral margins, which are prolonged into rounded plates, and are directed, when at rest, towards the mesial line of the body, and terminated by a broadly ovate recurved hand, with a short, strong, bent claw at its extremity, employed for prehension. The female is five or six times as large again as the male, being pear-shaped and unsymmetrical in its form, generally curved to one or the other side, and very much depressed, so that it assumes the appearance of a shield, having the lateral margins rather dilated and elevated, the lateral line of the segments being more BOPYHUS. 215 continuous than in the male. The head also is immersed in the anterior segment of the body, its front margin forming a continuous curve with that of the body. The antennae are even smaller and more rudimental than those of the male, the outer pair being apparently only three jointed, and the inner pair only two jointed. The mouth is comparatively rudimental in its structure, and is nearly concealed by a pair of oval operculiform foot-jaws, of which the anterior extremity is furnished on its inner edge with a small flattened and biarticulate appendage ; beneath these foot-jaws and near their base are several minute lobes ; the lower lip, on the contrary, is well developed, and forms with the labrum and man- dibles a sort of conical sucker, the mandibles being minute, pointed, and scarcely movable. The pereion is broad and flat, and the seven segments of which it is composed are closely soldered together, the lateral portions forming a rather strong border, beneath which are affixed the seven pairs of short, strong, prehensible feet, resembling those of the male in form. They are very small, so as not to extend beyond the sides of the body, and each is furnished at the base with a large plate-like appendage or valve, generally folded inwards, so as to form an incubatory pouch, which does not, however, entirely cover the central part of the underside of the body, leaving a wide open space, which allows the eggs and young to be seen ; the anterior of these plates differs in form from the rest, and seems rather to be transformed into an appendage of the mouth, having its lower extremity obtuse, free and curved (fig. f). The pleon in this sex is broad at the base, but narrower than the pereion, and gradually decreases in 216 BOPYRID^. breadth to its extremity, which is rounded, the six segments of which it is composed having the lateral margins thinner than those of the body ; on the upper side the articulations are almost obliterated, whilst its lower surface is covered with five pairs of pleopoda, each consisting of a single membranous plate of a somewhat triangular form, the terminal segment being destitute of any lateral appendage. The genus Bopyrus was established by Latreille in one of his earliest works, and was placed by him amongst the Isopodom crustaceans, being, in the first edition of the " Regne Animal," placed at the end of the order, with the view of showing what might be regarded as its organic degradation as compared with the other animals of the order. In the second edition of the same work, however, Latreille placed the genus at the begin- ning of the order, in a section termed Epicarides, with the view of bringing it into close connection with the Cymo- thoades, with which it has an evident affinity. In 1772, M. Fougeroux de Bondaroy published a memoir on B. squiltarum,* in which he completely dis- proved the old fallacy entertained by fishermen on the coasts of France, that the Bopyri were the young of soles or other flat fish which took shelter under the shell of the prawn to protect them in the early state of their existence — an idea which even Deslandes had held and recorded in the Memoires de 1'Academie Royale des Sciences de Paris in 1772. In 1837 some interesting observations upon the genus were published by Heinrich Rathke, " De Bopyro et Nereide. Rigae et Dorpati," 4to ; also in his work on morphology, " Reisebemerkungen aus Tamien." * Hist, de 1'Acad. des Sciences, 1772, p. 29, t. 1. BOPYRUS. 217 The females observed by him were five lines, and the males a line and one-third long. The former were in- variably found upon female prawns, of which he had observed several hundreds thus infested, whilst quite as many male prawns which he had observed were found to be free from their attacks. The mode of attachment of the parasites and the various and peculiar species of Crustacea on which they subsist is worthy of some consideration. They apparently work in pairs and only so, and from the following isolated observation would seem to do so from their earliest stages. Some little time since, having been requested to examine some Crustacea brought home from Australia, we found a shrimp (Caridina truncifrons*} laden with ova, amongst which we perceived two specimens of the larva of a Bopyroid crustacean, a circumstance that appears to throw some light on the subject, by suggesting the supposition that the larval Bopyri first take shelter among the freely hanging ova previously to their finding their way beneath the branchial walls of the carapace, and so having quitted the care of their own parent, they are fostered by another, on whom probably at a later period they prey parasitically. * Proc. Zool. Society, Nov. 24, 1863. 218 1SOPODA. NORMALIA. BOPYRIBvE. BOP YRID.E. BOPYRUS SQUILLARUM. Specific character. Male. Narrow, with the sides of each segment of the pereion produced into a flattened, rounded lobe. Pleon having the segments confluent. Antennte concealed beneath the cephalon. Female. Unsymmetrical, dilated at the sides. Pereiopoda small, strong, sub-equal. Anterior scales of the incubatory pouch curved, obtuse, and free. Length of the male 1 line ; of the female 4 or 5 lines. Bopyrus Squillarum. LATREILLE, Hist. Nat, Crust, et Ins. vii. p. 55, t. 59, f. 2. Gen. Crust, et Ins. i. p. 67, t. 2, f. 4. LAMARCK, Hist. Anim. sans Yertebr. v. p. 164. DESMAREST, Cons. Crust, p. 325, pi. 49, f. 8—14. GUERIN MEXEV. Icon. R. Anim. Crust, pi. 29, f. 2. BRULLE, Exped. Moree, p. 46. MONTAGU, Trans. Linn. Soc. ix. 105 BOPYRUS SQUILL ARUM. 219 (Oniscus sq.). GOODSIR, in Ann. Nat. Hist. x>. p. 75, pi. 7. MILNE EDWARDS, Crust, iii. p. 282. WHITE, Cat. Brit. Crust. (Brit. Mus.) p. 82. Pop. Hist. Brit. Crust, p. 256. Monoculus Cranyorum. FABRICIUS, Ent. Syst. Suppl. p. 306. Bosc, Hist. Crust, ii. 216 (Bopyrus cr.). Insecte qui £ attache a la brevette. FOUGEROUX DE BONDAROY, Mem. Acad. Sc. 1772, p. 29, t. 1. (Var. ?) Bopyrus Palcemonis. Risso, Crust, de Nice, p. 148. LAMARCK, Op. Cit. p. 165. DESMAKEST, Crust, p. 326. THIS species lias long been known in consequence of its occurrence, during the summer months, beneath the carapace of the common edible prawn, the presence of the female causing a large tumour, of nearly half an inch in diameter, on the side where the parasite affixes itself. The female, in the ordinary condition, is flat- tened and broadly ovate in form, and the minute male is generally to be found fixed amongst the respiratory plates on the underside of the tail of the female. The male closely resembles one of the Idotece in miniature, having the body elongate and narrow, with rounded, flattened lobes at the sides of the segments of the body, and with the tail of a reversed, triangular form, rounded at the tip, with the six segments only indicated by five incisions on each side, being confluent on the disc. The antennae are very short, and resemble those of the female, and the legs are also very short, although strong and ch elate. The female is broadly ovate, but having the pleon somewhat narrower than the pereion, flattened and curved either to the right or left,* according to the side This curvature is occasioned by the unequal pressure from the carapace of the prawn. 220 BOPYRILLE. of the prawn to which it has been affixed ; hence, in our right-hand figure, representing the dorsal view of the female, the head is seen to the left of a straight line, the lateral margins of the body to the right being distended, whilst those of the opposite side are contracted in a corresponding degree; the head itself does not project beyond the general outline of the body, which is almost continuous, and its anterior edge is rather sharp ; the hind part is considerably contracted, and very deeply immersed in the anterior segment of the body ; the eyes are wanting in this sex. The antennae are very small, the outer pair being composed of three short, broad joints, gradually diminishing in size, the last terminating in a minute point, which may possibly represent the flagellum ; the inner pair appear to be only formed of t\vo distinct joints, of which the basal one is nearly circular. The rudimental mouth is covered by a large pair of foot-jaws (maxillae), flattened, with the inner margin (where the two meet together) nearly straight, the inner apical angle being provided with a small, nearly circular, lobe or joint, clothed with small hairs, and the base of this pair of foot-jaws is furnished with two or three membranous, flattened, pointed appendages. The an- terior pair of the scales forming the incubatory pouch are transverse, and furnished with a large, flattened, curved lobe, of which the extremity is obtuse and in- curved. The other scales are affixed within the base of the legs, the hinder extremity of each overlapping the succeeding scale. The seven pairs of legs are of equal size and similar in form, being short and thick, having a broad, oval hand, terminated by a small finger. They are generally folded back and concealed beneath the lateral margins of BOPYRUS SQUILLARUM. 221 the body. The respiratory scales on the underside of the tail are short and transverse ; the basal segment of the tail is much shorter than the following, the second and three succeeding being of equal size, whilst the sixth is rather narrow and nearly truncate, without any appendages. The female when alive is of a pale greenish colour, glossy above, with the head and oral plates black, and those of the ovisac and under surface of the head black or very dark at their edges. The young Bopyri, before they leave the incubatory pouch of the females, are ovate in form, and dorsally convex, resembling very minute wood-lice, with the outer pair of antennae greatly elongated, composed of four joints, of which the first is short and robust, and the others elongated and terminated by one or two very long and slender setse. The legs are broadly sub-cheli- ferous, especially the four posterior pairs, the three anterior pairs being rather more slender and directed forwards, whilst the four latter pairs are directed back- wards. The respiratory scales of the tail (pleopoda) are strongly setigerous, the posterior pair being composed of a very short basal joint, supporting two elongated rami, pointed, and tipped with one or two terminal setae. The females of this species are attached to the outer lining of the branchial cavity of the common prawn, a single parasite being found upon an individual prawn. The fecundity of these parasites is very great, the eggs being retained within the incubatory pouch where they are hatched, and M. Risso states that he had counted as many as eight hundred young ones nourished by a single female. Mr. Adam White, upon the authority of Col. Mon- 222 BOPYRID^. tagu, states that this species is common also under the carapace of the shrimp. It has not been our experience to meet with one, those that we have seen being obtained from prawns. From Guernsey and Jersey we have re- ceived them from the Rev. A. M. Norman, on Palamon serratus and Pal&mon Leachii} and from Polperro, where Mr. Lough r in has found them on Palcemon serratus. The late Harry Goodsir published figures of a species of this genus, which he names B. Squillarum, representing the male, female, and young, which he had obtained from the carapace of a new species of Hippolyte (H. ensi- ferus) found in the gulf-weed between 25° and 30° north, and 40° west longitude. His figures, unfortunately, do not show sufficient care in their delineation, the seg- mentation of the body of the female being unintel- ligible, whilst the figures of the ambulatory legs of both sexes differ so materially from those organs in our English specimens, as to lead us to suppose that they cannot belong to this genus, but either to Bopyroides of Stimpsoia, or to Gyye. BOPYRID.E. 223 I SOP OVA. B OP YRJDM. NORM ALIA. Genus — GYGE, CORNALIA AND PANCERI. Mem. Acad. Reale di Torino, Ser. 2, t. 19 (1861), p. 85. Male. Cepbalon as broad as first segment of the pereion. Pereion long and narrow, segments subequal in length. Pleon short and broad, segments distinct and subequal in length with those of the pereion. Eyes small and situated at the posterior part of the cephalon; second pair of antenme well developed. Female. Oval, anteriorly slightly un symmetrical. Pereion, having the segments subequal, except the first two, Pleon having the segments distinct and subequal with those of the pereion. Antennae rudimentary. Branchial appendages consisting of a series of small single sacs attached within the ventral lateral extremity of the several segments of the pleon, and a series of transverse folds between them. Posterior pair of pleopoda slightly developed. THIS genus is certainly near Bopyrus, but differs from it in important structural conditions. It must also be very closely allied to the genus Bopyroides of Stimpson, which that author has formed for those species that agree in shape and structure with Bopyrus, but differ in their branchial features, in having " merely fleshy ridges instead of laminae." From the female Bopyrus and therefore also from Bopy- roides this genus differs in shape, being roundly oval, and not having the pleon narrower than the pereion ; moreover, in this genus the segments are distinct, in which it coin- cides with Stimpson's description of Bopyroides, whereas in Bopyrus they are all fused together in the central dorsal axis. Bopyrus, also, is unsymmetrical throughout, 224 whereas Gyge is only so at the anterior portion of the animal. It also differs in the more rudimentary condition of both pairs of antennae, and in the larger development of the ovigerous plates. The male is in proportion much larger, being nearly one- half the length of the female. It has also the cephalon proportionately larger, and the antennae, particularly those of the second pair, largely developed. The segments of the pleon are distinct, anteriorly being nearly as large as those of the pereion, and decreasing in length and breadth posteriorly very rapidly ; whereas in Bopyrus they are fused together except at the margins, smaller than those of the pereion, and decrease gradually. The larvse of this genus appear to correspond very closely with those of Bopyrus} but appear to have the antennae laterally nearer to one another. BOPYR1M. ISOPODA. NORMALLY BOPYRIDJS. GYGE GALATHE^E. Male. — Cephalon roundish, nearly as broad as the first segment of the pereion. Pereion increasing in breadth posteriorly. Pleon decreasing in breadth posteriorly, last segment bifurcate. First pair of antennae short, three-jointed ; second pair about three times the length of the superior, and terminating in a small flagellum. Female. — Flat, oval, slightly uusymmetrical. Cephalon broad, pleon short and continuous with the pereion, terminal segment having a pair of pleo- poda (posterior pair) projecting beyond its extremity and giving a bifurcate appearance to the posterior margin. Antennae rudimentary. Branchial appendages consisting of small sacs near the margin of the ventral surface of each segment of the pleon. Length of the male, three-twentieths of an inch. ,, ,, female, eight -twentieths ,, THE male gradually increases in breadth from the head to the last segment of the body (pereion), from which the segments of the tail rapidly decrease, thus giving the general aspect of a long narrow animal, with a large round VOL. II. Q 226 GYGE GALATHE.E. flat tail, which is the broadest part of it. The head is very nearly circular, flattened slightly at the anterior margin and cut off posteriorly by the first segment of the body, but still forming more than a semicircle. The first segment of the body is as long as and scarcely broader than the head ; the lateral margins are square. The six following segments are of the same length as the first, but gradually increase in breadth and become more and more pointed at the lateral margins, as they proceed towards the posterior extremity. The first segment of the pleon is somewhat less in length and breadth than the last of the pereion. The remain- ing segments decrease until the fifth, which is very small, and forms with the sixth a small forked extremity. The eyes are small, irregular patches of black pigment situated near the latero-posterior angles of the head. The first antennae are small, and scarcely reach to the anterior margin of the head ; they consist of two joints, each as broad as long, and a third that is much smaller and tipped with cilia. The second pair of antennae are nearly three times as long as the first, and project beyond the lateral margins a considerable distance ; they consist of five joints, and a minute triarticulated flagellum. The first three joints are subequal in length and diameter, the fourth is narrower and longer than the preceding, the fifth is still narrower and short, and appears to form the basal part of the small triarticulated flagellum, which supports, as well as the three preceding joints, a few short hairs. The organs of the mouth form a central conical process, but they have not been dissected out. The first pair of feet (first pair of gnathopoda) are large, strong and subchelate, the palm is concave, and the long curved dactylos impinges by the apex only against the dental projection of the posterior angle of the palm. The second and succeeding pairs of limbs gradually but GYGE GALATHE.E. 227 considerably decrease in the dimensions of the prehensile portion, and have the palm somewhat convex and serrated, the dactylos short and thick. There appears to be no distinct pleopoda or branchial appendages of any kind, but the thin lateral extremity of each segment appears to be considerably attenuated and to be traversed by numerous channels, which must necessarily assist very considerably in bringing the vital fluids into close approx- imation with the oxidizing influence of the water. The female is oval, broad, but little more than half as long again as the male. Anterior portion of the animal only, unsymmetrical. Head partially fused with the first segment of the body, first segment short, the second scarcely longer, the five posterior segments subequal, longer than the first two. Those of the tail (pleon) gradually decrease until the sixth, which terminates in a small forked extremity, being the rudimentary condition of the posterior pair of pleopoda, which are so largely developed in the larval condition. The eyes are wanting. The antennae are rudimentary, each pair consisting of a single basal joint, not longer than broad, and an apical small spine or second joint. The oral organs converge to a point, and are situated below and between the antennae ; these are covered and protected by the maxillse, and the oral appendages deve- loped in the form of large fleshy scales, somewhat similar to but thicker than the ovigerous plates that spring from the base of every leg. The pleopoda or branchial appendages consist of small sacs attached close to the under surface near the extremity of each segment, while a membranous ridge or fold reaches from one extremity to the other. The young animal as it appears when just able to quit the parental pouch, is dorsally arcuate, the cephalon Q 2 228 GYGE GAJATHE/E. • anteriorly broad and projecting hood-like over the an- tenna?. The segments of the pereion are all present as well as those of the pleon, with which they are subequal, the last segment terminating in a central tubular process, the extremity probably of the alimentary canal. (See the upper right-hand figure.) The eyes are small, irregular blotches, situated within the lateral and near the posterior margin of the cephalon. The first pair of antennae are rudimentary, consisting of a basal joint of tolerably large proportions, and a ter- minal triarticulate fiagellum. The second pair are more than half the length of the animal, and consist of three (or four ?) large joints and a terminal slender one tipped with four hairs, one of which is very long and strong and two very short. The four anterior pairs of legs have the propodos round and the dactylos short and curved, the three posterior pairs have the propodos long, narrow, and the dactylos straight. The last two differ from the ante- penultimate in having the carpus produced along the inferior margin of the propodos to the posterior angle of the palm. The pleopoda are five pairs, and consist of a series of foliaceous plates tipped with an external long and an internal short hair. The posterior pair of pleopoda are biramous, each branch being biarticulate, terminating in a fine hair-like point. The specimens from which these descriptions are taken were procured by the Rev. A. M. Norman at Herm, in Guernsey, on a specimen of Galathea squamifera. With the exception of a difference in the habits of the species, the one above described seems (so far as we are able to judge from the description and figures of both sexes, given by Messrs. Cornalia and Panzeri in their elaborate memoir above referred to of G. branchialis, which infests Gebia Venetiarum and littoralis], scarcely GYGE GALATHE^E. 229 to differ from the Italian animal, agreeing therewith, especially in the peculiar form of the male. The following vignette of the Cliffs of Whitenore, in Weyniouth Bay, has been kindly sent to us for this work by Mr. Thompson, of Wey mouth. CLIFFS AT WHJTENORE, WEYMOUTH BAY. 230 BOPYRUXE. ISOPODA. NORMALIA. BOPYRID^E. '/ GYGE HIPPOLYTES. Male. — Sides subparallel ; antennae, advanced beyond the front of the head; segments of the pleon fused into an elongated ovate mass, obtuse at the extremity. Female. — Broadly ovate, depressed, anterior portion slightly curved towards the left (when viewed dorsally) ; segments of the pereion and pleon distinct, sub-continuous ; terminal segment apparently notched at the tip, owing to the projection of the posterior pair of pleopoda. Length : — Female, seven-twentieths of an inch. Bopyrus Hippolytes. KROYER, Gronlands Amfipoder Besck, p. 78, pi. 4, fig. 22. MILNE EDWARDS, Crust. 3, 283. WHITE, Pop. Hist. Brit. Crust, p. 256. THE male of this species is narrow, with the sides of the body almost parallel ; the head transversely ovate, with minute eyes and with the four antennae short, conical, subequal, and advanced beyond the front margin of the head ; the segments of the body are rather wide apart at the sides, and those of the tail are confluent, forming an GYGE HIPPOLYTES. 231 apparently inarticulate mass of an elongate ovate form, somewhat truncated at the base, scarcely with indications of divisions between the joints, the extremity being entire. The female is broadly ovate, with the body slightly curved towards the left, the segments distinct, especially those of the tail, which is terminated by a small joint notched at its extremity, two minute pleopoda of an elon- gate-ovate form arising on its underside and having their ends visible within the emargination of the joint. The head is broad, furnished on its underside with two pairs of minute conical antennae, the inner pair consisting of three, and the outer pair of four joints, the penulti- mate of which is slightly setose, and the last terminated by a minute fascicle of setse ; the seven pairs of feet are small but robust, and of uniform size and shape, termi- nated by an elongate- ovate hand with a minute but strongly hooked finger ; the two preceding joints being rather rugose at their extremities on the underside. This species was first described by Kroyer, who de- tected it as a parasite on a species of prawn of the genus Hippulyte (H. polar is) t A specimen of this species is recorded as having been taken by the late Mr. W. Thompson, of Belfast, on the coast of Galway. The specimen belongs to the Belfast Museum, and is, unfortunately in a damaged condition. Another specimen (of the female), which appears to us to belong to the same species, and which has supplied the central figure in the above woodcut, was forwarded to us from Polperro by Mr. Loughrin ; our two lower-side figures being copied from Kroyer's figures of the male and underside of the female. 232 BOPYR1D.E. ISOPODA . BOP YRID^E. NORM ALIA. Genus— PHRYXUS, RATIIKE. (Phryxus and Pleurocrypta, HESSE.) THIS genus was instituted by Rathke, for the reception of a species of the Bopyrida, parasitic on a prawn of the genus Hippolyte, remarkable for the very swollen and unsymmetrical form of the female, of which the legs on one side are nearly abortive in the full-grown state, but more especially for the large size of the lobes or plate-like branchial appendages of the tail, by which it at once differs from the two preceding genera. The whole of the species hitherto discovered, including three new ones now first made known to the public, are parasites on various crustaceous animals belonging to the Anomourous and Macrourous divisions, including not only the more typical Hippolyte, but also the aberrant genera Pagurus and Galathea. The male in the species which served for the establish- ment of the genus is very minute and elongated in form, with the head transversely ovate, with two minute dark points indicating the eyes ; the upper antennae are very minute, and consist of three joints of equal length, but gradually becoming more slender to the tip, which is furnished with a number of hairs ; the lower antennae are much longer, and consist of eight joints, also gradually attenuated to the tip. The mouth is transformed into a small conical protuberance rising from a semicircular space. The pereion is composed of seven segments of nearly equal size, each with the sides rounded and wide apart (in specimens distended from having been PHRYXUS. 233 immersed in spirits), hence the body is nearly parallel at the sides. Each segment bears a pair of rather strong legs, formed for walking, terminated by a semi-ovate hand, with a sharp hook-like finger. The pleon forms a subconic-ovate mass, with all the segments closely soldered together, indicated more or less distinctly by lateral incisions. The full-grown female is a large inert nearly globular mass, with the segments scarcely indicated by depressions, and with a series of wide and broad ovigerous plates, which fold backwards and envelop the upper-side of the body. The cephalon is furnished with very short antennae, resembling those of the male in structure, and the mouth forms a large conical tubercle rounded at the extremity. The pereiopoda are inclined towards the back, and formed as in the female Bopyri, with the articulations much less distinct than in the males, and the propoda are small and weak, with a small curved obtuse dactylos. These limbs are irregular in size on the two sides of the body, some of them being even obsolete on one or other side. The pleon is composed of small joints, furnished with elongated lobes or plates for breathing, varying in number and size in the different species, the terminal joint being small and bifid in the typical species. We have added to the genus several species, the females of which possess more or less elongated appendages to the segments of the tail, but differ from the typical species in having the body in the same sex symmetrical, or nearly so ; on this account one of these species has been formed by M. Hesse into the genus Pleurocrypta, which we have not thought necessary to retain. 234 ISOPODA. NORM All A. BOPYRID2E. BOPYRID^E. PHEYXTJS ABDOMINALiS. Male. — Upper antennae very short, three-jointed; second antennae eight- jointed, gradually attenuated to the tip. Oblong, subdepressed, with the pleon produced into a short blunt point. Female. — Subglobose, very unsymmetrical, with the pereipoda on one side of the body almost obsolete. Pleon furnished on each side with four large oblong-ovate fleshy lobes ; terminal segment minute. Length of male, one-tenth, of female, one-quarter, of an inch. Bopyrus abdoininalis. KKOYEK, Natur. hist. Tidsk. iii. p. 102 — , 289, pi. 1, 2 (1840); Voy. Scandinav. Crust, rl. 29, fig. 1. Phryxus Hippolytes. EATHKE, in Nova Acta Acad., Nat. Curios., xx. p. 40, tab. 2. figs. 1—10. WHITE, Pop. Hist. Brit. Crust, fig. 257, pi. xiv. fig. a, male; b, female (1843). THE male of this species is extremely minute, and is generally to be found partially immersed between the folds of the posterior part of the body of the female. The head is transversely ovate, with both pairs of antenna} visible in front. PHUYXUS ABDOMINALIS. 235 The mouth in the full-grown male, in which probably but little food is taken, is reduced to a small conical fleshy lobe on the underside of the head. The seven segments of the body are quite distinct, and the seven pairs of legs are affixed near the sides of the body beneath, and may be extended considerably beyond the sides, although generally hidden by being folded inwards close to the sides when at rest. The tail forms a subconical piece, having all its seg- ments closely soldered together with very slight indica- tions of the articulations. The female, when full-grown and distended with eggs (of which the number is immense), forms a large, nearly globular, mass, with one side of the body swollen to such a degree that it extends far beyond the limits of the head, absorbing the legs on this side, with the exception of the most anterior. This is exhibited in the lower figure on the left-hand side of our woodcut, where the mouth is in- dicated by the small dark-shaded portion resting on a somewhat heart-shaped base, having a leg with a dilated basal joint on either side, that of the right side succeeded by a series of folds, within which are attached the bases of the succeeding legs, whereas those of the left side are obsolete. These legs are slender, and terminated by an oval hand with a weak and curved finger, obtuse at its tip. The sides of the body of the female are provided with very large scales, not arranged in pairs, and which fall backwards so as to cover the body. The tail consists of five segments, of which the four basal ones are short and narrow, having on either side a large and a small fleshy lobe of an oval shape, but varying in size according to the side of the body to which they are attached ; being the largest on the dilated side. The 236 PHRYXUS HIPPOLYTES. terminal segment is minute, and unfurnished with ap- pendages. In Rathke's dorsal figure of the species this segment is represented as bifid, but in the ventral one as entire, as appears also to be the case in our individuals. We have no hesitation in regarding our specimens as identical with Bopyrus abdominalis, elaborately figured in all its details by Kroyer in 1840, which is represented by him as attached to the under surface of the pereion of a species of Prawn. The young of this animal is oval and very convex, with very slight indications of articulations ; the head isjarge, with two dark round spots indicating the eyes ; the upper antennae are short and apparently exarticulate, whilst the lower pair of antennre are about half the length of the body and six-jointed, with a pencil of terminal hairs. The body is furnished beneath with six pairs of strong subcheliferous legs, and the hinder part of the body, re- presenting the tail, is provided wTith five pairs of flattened elongate-ovate plates, strongly ciliated at their extremi- ties, the small obtusely triangular terminal segment being, moreover, furnished on each side with a larger curved lobe, bisetigerous at its tip. This species was first detected by Herr Rathke as a parasite beneath the shell of a species of Hippolyte. We are indebted for our knowledge of it as a British species to Mr. Frederick Bond, an excellent ornithologist and entomologist, who obtained both sexes from the underside of the tail of the white Shrimp of the Sussex Coast, Pandalus annulicornis, in the month of April, 1846. Mr. Alder has also obligingly forwarded to us a spe- cimen of the male on Hippolyte Barleei, taken at Culler- coats, on the Northumberland Coast. So firmly was the little parasite attached to the ventral surface of the pereion between the fifth pair of pereiopoda, that it was PHRYXUS ABHOMINALIS. 237 necessary to remove the creature with an instrument. This abnormal position was evidently one of some duration, for there had been no female attached to the Hippolyte, and the parasite, instead of being white and bleached as these creatures generally are, was of a reddish brown, and of hard structure. The following vignette is a sketch of the Bay of Bayndie, near Banff, taken by Mr. Greig from the Elfkirk. It is in this bay that many of the observations on the Crustacea were made for us by Mr. Edward, to whom we are indebted for the next species. 0 JEWITT • BAY OF BAYNDIE, BANFF ; FROM THE ELFKIRK. 238 ISOPODA. NORM A LI A. BOPYRIM. BOPYRID&. (J PHRYXUS FUSTICAUDATUS. Female. — Oval, nearly symmetrical, the segments of the pereion clearly indicated by lateral incisions; antennae, prominently seen beyond the fore margin of the head ; pereiopoda swollen, with indistinct segments terminated by a small claw with a minute dactylos. Pleon well defined, composed of four segments narrower than those of the pereion, and furnished at the sides with four elongate-clavate simple lobes ; terminal segment forming an elongate- oval mass. Length, one-tenth of an inch. THE small but increasing size of the few specimens of this species which we have hitherto seen, all of which are females, their symmetrical form, and the want of develop- ment of the scales in which the eggs are enveloped, lead us to suppose that the individuals before us are not yet arrived at the full growth. The curious lateral appendages at the sides of the tail are more strongly developed than in any other species we have yet seen, and their number agrees with that of the same organs in Ph. Hippolytes. PHRYXUS FUSTICAUDATUS. 239 The head is broadly semicircular in form, the middle of the anterior margin produced into a conical lobe repre- senting the organs of the mouth, at the sides of which are affixed the two pairs of antennae, varying in length as above described in the characters of the genus. The body is oval, with the sides symmetrical, the seg- ments well marked by incisions, with the sides of the segments themselves rounded ; on the underside the seven pairs of swollen obtuse feet are affixed, near the sides of the body, each being terminated by a small claw with a minute obtuse finger. The four basal segments of the tail are very much narrower than those of the body, and become gradually narrowed to the fifth or terminal joint, which forms a large clavate mass ; the sides of each of the four basal segments of the tail are furnished with a pair of elongated clavate appendages for breathing. We have only seen three specimens of this species, which were discovered by our valued correspondent, Mr. Edward, of Banff, attached to the branchiae of the common Soldier Crab, Pagurus Bernhardus, on the 12th December, 1864'. 240 ISOPODA. NORM ALT A. BOPYRID.E. BOPTRID^. PHRYXUS PAGURI. Male. — With the cephalon nearly as broad as the joints of the pereion, with two minute eyes. Aijtennse and pereiopoda not porrected in the front or extending beyond the sides of the body. Pleon narrower than the pereion, having the three anterior segments indistinctly defined. Female. — Broadly ovate, nearly symmetrical, with very large ovigerous scales. Pereiopoda robust, of considerable size, equally developed on each side of the body. Pleon with the four anterior segments defined ; each provided on each side with, a pair of subglobose lobes attached by short foot-stalks to a common slender base. Length of the male, one-eighth of an inch ; of the female, nearly half an inch. Phryxus Paguri. RATKKE, in Nova Acta Acad., Nat. Curios., xx. p. 57, tab. 1, figs. 13-15, male ; tab. 2, figs. 11, 12, female. OUR figures of this species are copied from a very careful series of drawings, made by our friend Mr. Robert Templeton, from specimens taken from a Pagurus, dredged off Bird Island, Strangford Lough, in from eight to ten fathoms deep, with a muddy and shelly bottom, by Mr. PHRYXUS PAGURI. 241 G. C. Hyndman, August 16, 1848, corrected by an ex- amination of Mr. Templeton's specimens. The male is very minute, elongate-ovate, with the tail more slender and indistinctly articulated. In Rathke's figure, the segments of the body are represented as much more widely separated from each other at the sides than in our specimen, the anterior lateral angle of each segment being rounded, and the middle of the hinder margin more rounded behind ; the upper antennse are very minute and three-jointed, the lower pair are longer, and seen beyond the lateral margin of the head ; the legs are small, terminated by a small ovate hand with a minute hook-like finger (dactylos). The female is large and unwieldy, with very large ovigerous scales. The body is but slightly unsymmetrical, nearly oval in form, with the ovigerous scales very large and thrown over the back, entirely concealing the body, limbs, and tail of the animal, where the latter is incurved ; the head is oval, with the inner antennse very small, com- posed of a thick basal joint and a minute terminal one ; the outer pair are much larger, apparently three-jointed, terminated by a thin bristle. The legs are well developed on each side of the body ; they are strong and terminated by an oval hand, having a minute emargination for the reception of a small finger. The tail is composed of four transverse segments, each furnished on each side with a pair of nearly globose lobes, fixed by short footstalks to a short and slender base. The tail is termi- nated by a small joint supporting a single lobe like the rest, so that there are seventeen of these appendages in all. Our figures represent the upper and under sides of the female, with the head, one of the feet, and a pair of the lobes of the tail, and the minute and slender male. VOL. IT. R 242 BOPYRID^E. In addition to Mr. Templeton's specimens, we have received the male and female of this species from Pol- perro, collected by Mr. Couch, as well as a coloured drawing of a specimen which we also consider to belong to this species from St. Andrews ; having been taken by Mr. Mclntosh. It was first found by Rathke upon Pagurus Bernhardus on the Norwegian shore. Athelgue fidlode of M. Hesse, Ann. Sc. Nat., ser. 4, vol. xv. p. 97, pi. 9, appears to us to belong to this species. With reference to the question how the Bopyrus can survive when the crab throws off its exuvium, Dr. Fritz Miiller writes to us — " When the crab casts its skin, there can be no doubt but that the Bopyrus must go along with it ; but as the crab, immediately after exuvia- tion, is in an almost helpless and motionless condition, I think that the Bopyrus may crawl again into the branchial cavity. I shall send you a Porcellana, the integuments of which are so soft that it must have moulted very recently, and notwithstanding it has a very large Bopyrus in its branchial cavity. Moreover, it seems to be im- possible that the considerable deformation of the carapace of the crab produced by the Bopyrus could disappear by exuviation ; but I never found a deformed carapace with- out the Bopyrus, although I have examined more than a hundred Porcellanse bearing the parasite." — " I may here observe, in Bopyrus Porcellanae the right side is more developed than the left when the parasite dwells in the right branchial cavity, whereas the left side is the larger when the Bopyrus dwells in the left branchial cavity. The Bopyrus being fixed with its head directed backwards naturally in the right branchial cavity, the right side of the parasite can freely extend downwards, and therefore becomes larger." 1SOPODA. NORMALIA. PHRYXUS HYNDMANNI. 243 BOPYRID^E. PHRYXUS HYNDMANNI. Female. Flattened above, ovate in outline, but slightly unsymmetrical. Pereiopoda equally developed on both sides of the pereion. Pleon having six segments, the segments being but little narrower than the hinder segments of the pereion, each furnished at each side with a flattened, rounded-oval scale or lobe, the two attached to the posterior segment being rather more pointed; on the underside are two rows of elongate, conical, fleshy lobes, obtuse at their tips, and slightly wrinkled transversely. Length, about one-third of an inch. WE are only acquainted with a single female individual of this species, found attached to a Pagurus obtained at Groomsport, Ireland, from ten fathoms depth, by Mr. G. C, Hyndman, on the 24th of May, 1851, and by him presented to the late Mr. W. Thompson, in whose col- lection it is still preserved. From Phryxus Paguri it is at once distinguished by the rounded flat scales at the sides of the segments of the tail, which, indeed, appear rather to be but the lateral extensions of the segments R 2 244 BOPYRHLE. than lobes analogous to those of Ph. Paguri, fustic audatus, &c. The body is rather broadly ovate, nearly symmetri- cal, the head being bent a little to the left ; flat on its dorsal surface, its ventral side being concealed by large ovigerous scales, which do not extend over the sides of the body so as to conceal the legs, which are not very robust. The antennae are very minute, and in the middle of the head, on the underside, is a small somewhat semicircular raised lobe. The segments of the tail are continuous with the hinder part of the body, the flattened lateral scales of the former rendering the joints nearly as wide as the latter, the pair of these scales attached to the ter- minal segment are directed backwards and are somewhat more pointed at their extremity. On the ventral surface of the tail are two rows of fleshy somewhat elongate cylindrico-conic appendages, obtuse at their extremities, and which when stretched out do not extend beyond the sides of the tail, and are consequently not visible from above. In addition to the specimens obtained from Hermit Crabs described above and in the following pages, we have received an exceedingly minute male, captured on a Pagurus Bernhardus on the coast of Durham, which we cannot satisfactorily assign to its legitimate partner. It is preserved in Canada balsam, and is of an elongate form, somewhat ovate in its general outline, with the • sides of the segments of the body and tail regularly rounded, without any wide interval between them. The outer antennae are sufficiently large to extend beyond the sides of the head ; they are three-jointed and seti- gerous at the tip, and the inner antennse are extremely minute and two-jointed ; the mouth appears to consist of a conical tubercle in the middle of the lower surface of the PHRYXUS HYNDMANNI. 245 head. The legs are very robust, but folded so as not to extend beyond the sides of the body. The tail is com- posed of six joints, gradually diminishing in width, the last being very small, nearly oval, the tip pointed, and with a minute seta on each side beyond the middle. Dr. Fritz Miiller, in a letter to us dated in 1864, observes, that " One of the most interesting animals of this family is a Bopyrus living on Pagurus, in which the dorsal surface of the parasite is directed towards the Pagurus (I therefore named it B. resupinatus) . The origin of this curious manner of attachment is the following: — The larva of Bopyrus fixes itself to the Sacculina purpurea, living on the same Pagurus, and takes its nourishment from the roots of the parasite. After the death of the Sacculina, to whose ventral surface the Bopyrus was fixed, the latter probably cannot change its position, and remains with its dorsal surface facing the Pagurus." r V T V 246 1SOPODA. NORM All A. BOPYRID^. BOPYR1D&. PHRYXUS LONGIBRANCHIATUS. Male. Elongate, with the cephalon narrower than the pereion. The eyes very minute. The segments of the pereion nearly equal, laterally separated from each other by a considerable interval. Pleon composed of an elongate ovate-conic piece, in which the segments are fused together. Female. Ovate, flattened, slightly unsymmetrical, curved a little to the left when viewed dorsally. Pleon with the six segments well defined, narrower than the pereion, furnished with a pair of elongate fleshy lobes on each side of each segment, and with four attached to the -terminal segment. Length of the male, one line ; of the female, about one-fifth of an inch. THIS species is at once distinguishable from Phryxus Hippolyte and Ph. fusticaudatus by the greater number of fleshy lobes at the sides and extremity of the tail of the female, as well as by their different formation, which latter character separates it from Ph. Paguri. The male has the segments of the body of nearly equal width through- PHRYXUS LONGIBRANCHIATUS. 247 out, the sides dilated laterally, with the anterior lateral angles of each rounded off so that there is a considerable interval between the segments. The tail, on the contrary, has all the joints soldered into a solid piece. This sex is furnished with very short, smooth legs, terminated by a hand much larger than the preceding joints, with a rather strong curved movable finger. The female is oblong-ovate, flattened, slightly curved towards the left, so as not to render it very unsym- metrical. The eyes are very minute, the sides of the segments impressed, with the legs inserted within the impressions ; they are strong, with the intermediate joints as large as the hand, and rugose on their underside. The tail is about half the length of the body, nar- rower than the terminal segments of the latter, each joint furnished at each side with a pair of elongate fleshy somewhat cylindrical lobes attenuated towards the tip, the terminal segment being furnished, as appears to us, with four of these lobes (one of the four being repre- sented as attached to the left-hand pair of the fifth segment in the right-hand figure of the woodcut illus- trating this species). This species bears some resemblance to Bopyrus folio >- sus of Kroyer, Voy. Scandinave, Crust., pi, 29, fig. #, but the rounder form of the pereion, the more elongated tail, and the different form and apparent number of the ap- pendages of the tail, and especially those of the terminal segment, at once distinguish the last-named species from the one before us. Kroyer's specimens, indeed, appear to form a connecting link between Phryxus and Athelges cladophora of Hesse. Our specimens of this species were forwarded to us from Shetland, by Mr. J. Gwyn Jeffreys. The Rev. A. M. Norman announces it from a specimen 248 BOPYRID.E. of Pagurus Thompsoni, dredged off Tynemouth, Aug., 1862. From Polperro we have received specimens of both sexes, captured by Mr. Loughrin, upon an old specimen of Galathea squamifera, of a much larger size than those represented above, the male being T\ths and the female }^ths of an inch long. They precisely agree in general form and in most of their details with the preceding. The feet of the male are, however, more powerfully constructed, with a semicircular emargination on the underside of the hand, but the dorsal appendages of the basal segments of the tail of the female are thicker and more rounded in form, whilst the lateral ones as well as the four attached to the terminal segment are more pointed at their extre- mities and corrugated along their surface. These differ- ences do not appear to us to be incompatible with the enlarged size of the individuals, presuming that those described and figured above are not full grown. PI111YXUS GALATIIKZK. ISOPODA. NORM ALT A. 240 BOFYRIDJE. V PHRYXUS GALATHE^l. Male. Elongate ; with the segments of the pereion rounded at the sides, especially towards the hind margin of each. Segments of the pleon distinct, transverse, rounded at the sides of each, narrower than the hinder segments of the pereion, terminal joint truncated at its extremity. Female. Ovate, flattened, and slightly un symmetrical, ovigerous scales of moderate size, finely ciliated on the margin. Pleon nearly triangular, joints transverse, furnished with a number of elongated corrugated fleshy cylindrical appendages, pointed at the tips. Length of the male one-sixth, of the female one-fourth, of an inch. Plcurocrypia Galathece. HESSE, Ann. Sci. Nat., 3rd ser. vol. iii. pi. 4. THIS species nearly resembles Ph. longibranchiatus in the general form of the female and in the elongated lobes of the tail of the same sex. It differs, however, in its habitat, being parasitic upon Galathea intermedia, and in the distinct articulations of the tail of the male. Our specimens of the two sexes are, however, preserved in 250 BOPYRULE. Canada balsam, and it is not impossible that they have been somewhat distorted, and which also precludes our examining them satisfactorily. The male (represented on the left hand of our woodcut of this species) has the segments of the body very dis- tinct and rounded at their sides, the posterior lateral angles of each being rather more rounded off than the anterior angles; the six-segmented tail is narrower than the hinder segments of the body ; its segments are, however, equally distinct and rounded at the sides, truncated at the hinder margin, the terminal segment being transverse, with the sides rounded, and the extremity truncated. The legs are strong and hooked ; when folded in their ordinary position, they nearly cover the underside of the body. The first pair of antennae are three-jointed and setigerous at the tip, whilst the second pair are five- jointed, the terminal joint being very minute. The small conical mouth appears to be protected on each side by a minute two-jointed footjaw. The female is broadly-ovate, with the ovigerous scales rather narrow and fringed with a few minute setse. Both pairs of antennae consist of three small joints ; they are minute, and somewhat conical in general form. The legs are longer, and comparatively not so strong as those of the male. The mouth is represented as it appears in our prepared specimen in the lower figure of our woodcut. The tail is nearly triangular in form ; it is furnished at the sides and beneath with elongate-conic fleshy appen- dages, the precise number and distribution of which we are unfortunately unable to describe, but suppose that there are two pairs to each of the six segments. Our specimens wrere obtained from Shetland in 1864, collected by the Rev. A. M. Norman. IONE. 251 1SOP ODA . NORM ALIA. Genus— IONE. (Latreille.) THIS genus is at once distinguished from all the other Bopyrida, except Argeia of Dana, by the possession of elongated branchial (?) appendages attached to the base of the six anterior pairs of legs in the female, and by the structure of the branchiae affixed at the sides of the tail in both sexes ; all of these in the male, and the posterior pair in the female, are elongated and filiform, whilst the pairs attached to the five anterior segments of the tail in the female are greatly elongated and multi-ramose, resembling pieces of coral. The male is minute, resembling those of the Bopyri, with the head distinct, the outer antennae prominently project- ing beyond the front margin of the head, the inner pair rudimentary, the seven segments of the body of nearly equal size and width (except the first, which is shorter than the rest) ; they are separated from each other by a considerable space, having the lateral margins somewhat angularly produced, the legs being affixed beneath the lateral angles. The legs resemble those of the male Bopyri, and are terminated by a small oval hand, with a small curved finger. The tail is narrower than the hinder segments of the body, and consists of six distinct seg- ments, gradually narrowing in size, each segment being furnished with a pair of elongated slender, cylindrical, membranous appendages (pleopoda). The female is much larger than the male, with the body flattened, pear-shaped, and slightly unsymmetrical. The head is transverse in front, its posterior portion being 252 BOPYRID.E. narrowed so as to resemble a shield, and embedded in the first segment of the body. Its anterior margin is dilated over the base of the antennae, the extremities of which extend beyond it. The inner pair of antennas are minute and rudimental ; the outer pair are larger, and composed of five joints, gradually attenuated, and ter- minated by a small articulated flagellum. The mouth is covered by a pair of lamellated foot-jaws, somewhat re- sembling those of the genus Cymothoa, and the mandibles are arranged as in the same group ; but, as described by M. Edwards, they are more slender towards the tip, and are destitute of any articulated appendage. The other parts of the mouth appear to be replaced by semi-mem- branous lobes, of which the precise structure has not yet been determined. The segments of the body are dis- tinct, with the lateral margins sub-continuous, but desti- tute of epimerae, thus disagreeing with the Cymothoce. The legs resemble those of the male ; each of the six anterior pairs are furnished beneath at the base with two appendages of considerable size, one being broad, folia- ceous, of a semi-corneous consistence, and folded beneath the body so as to assist in forming a large ovigerous pouch, covering the whole of the underside of the body ; the other being an elongated slender membranous fila- ment, which lies on the outside of the body, floating in the water, and resembling the branchiae attached to the legs of the Amphipoda. The tail is small and ovate, with the segments indistinct, except at the sides, where they are marked by slight incisions ; the appendages attached to the five anterior segments are elongate, and branched like a piece of coral, whilst the posterior pair are slender, cylindrical, and simple. Several of the basal appendages are, moreover, furnished at the base beneath with a small scale, lying beneath the tail. TONE. 253 The species are parasites on some of the most curious genera of macrourous Decapoda, the British species in- festing our only species of Callianassa. The only specimen of this genus that we have had an opportunity of examining was found on a Callianassa taken by Mr. Lord in British Columbia. It was very much larger than our British species, and is described as lone cornutus by Mr. Spence Bate in the " Proceedings of the Zoological Society" for 1864. The large size of the animal enabled us to examine the detail of its structure with comparative ease. Laden as it was with mature larvae, the large ovigerous plates covered the whole of the under surface except the pleon. We saw nothing of the delicate narrow membranous appendages attached to the legs that Professor M. Edwards supposes to be branchiae, like those of the Amphipoda. The organs of the mouth consist of several appendages much differentiated, and co-operating together so as to form one large oval mass, that wras evidently endowed with some degree of propulsive movement. The mandibles consist of a pair of long narrow plates that are serrated at the anterior edge, one being obliquely convex, the other concave : the one that is concave being convex nearer the base, while the reverse is the form of the other, so that the blades being each a little curved, the two meet at the point much in the form of a screw. These cutting appendages are planted at the extremity of the oesophagus, which, from its membranous character, probably has a contractile power. The two pairs of maxillae appear to be developed round the mandibles as a strong support and frame- work, the whole of which has the power of being pushed out or withdrawn by the assistance of powerful .: muscles that are attached to a strong osseous tendon <> 254 BOPYRUXE. near the middle of each organ. On each side, near the posterior extremity, exist two digital processes, the secondary appendages of the maxilla. The maxilliped consists of three primary joints, the first two being large and squamous, the third small and rudimentary. Posterior to the point where this joint articulates with the pre- ceding, lies the secondary appendage which, like those of the preceding pair, is digital in form, and points backwards. The appendages of the pleon consist of three kinds, namely, a primary branch minutely articulated through- out its length ; the basal articulus, which probably represents the coxa or first joint in the normal organ, supports two appendages, one large and saccular, being constricted at the base and pointed at the apex, the other long, narrow, symmetrical, and pointed. These two ap- pendages are constant on every pair of pleopoda, but bear an inverse proportion to each other. In the anterior pair the saccular branch is the more important, but this gradually diminishes on each to the last pair, where it is almost, if not quite, obsolete, whereas in the first pair the digitiform process is the smaller of the two ; this gradually increases on each succeeding pair of pleopoda, until in the last pair it forms the long pair of caudal processes seen so conspicuously at the extremity, and to which in this present species the male was attached by means of the subprehensile claw of the posterior pair of pereiopoda. To all the segments, except the last, are attached one or more of the numerous arborescent branches of which the mass of branchiae is built up. The male offers only specific variation from that of our British species. TONE THORACICA, I SOP 0 DA. NORM All A 255 BOP YRIDJE. TONE THORACICA. Male. — Narrow, subparallel, first segment of the body shorter than the following, the remainder with the sides subangulated. Female. — Pyriform, flattened, basal appendages of the tail multi-ramose. Length of female, about one-quarter of an inch. Oniscus thoracicus. MONTAGU, Trans. Linn. Soc. ix. p. 103, pi. 5, f. 3. Oniscus (lone) thoracicus. LATREILLE, Enc. Meth. pi. 336, fig. 46. lone thoracicus. LATREILLE, in Regne An. Ed. i. iii. p. 54. LAMARCK, Hist. Anim. sans Yertebres, v. p. 170. DESMA- REST, Cons. Crust, p. 286, t. 46, f. 10. GUERIN MENEVILLE, Icon. R. Anim. Crust, t. 62, f. 1, 2. MILNE EDWARDS, Crust, iii. p. 280, t. 33, f. 14, 15. CHVIER, Regne Anim. (Edit. Crochard) Crust, t. 59, f. 1. WHITE, B. M. Cat. Brit. Crust, p. 81. Pop. Hist. Brit. Crust, p. 254, pi. xiv. f. Sa (male), b (female). IT is to Colonel Montagu that we are indebted for the first knowledge of this interesting parasite, which inhabits the branchial cavity of Callianassa subterranea, concealing 256 BOPYRID^E. itself between the branchial appendages and the carapace, and forming a tumour on one side. From this situation he extracted it alive, and kept it in sea-water for several days. In all the specimens which he discovered the female was attended by the minute male, which was con- cealed amongst the arborescent appendages of the tail, to which it was affixed firmly by its claws. He adds, that the very disproportionate size of the sexes is wisely adapted to an animal whose habitation is so confined. As we are only acquainted with a single British species (which is also found on the north-west shores of France), it is unnecessary to redescribe the characters of the species, which are included in those of the genus given above. The colour of the animal is generally orange, with the appendages whitish. Our figures are copied from the beautiful ones published by M. Milne Edwards in the Crochard Edition of Cuvier's " Regne Animal/' that author having been enabled to examine recent specimens of both sexes. It was found by Colonel Montagu in the Kingsbridge estuary, on the south coast of Devonshire. The Callianassa on which it lives exists in galleries of its own excavation, about a foot beneath the surface of the sea bottom. Unfortunately, the specimen preserved in the British Museum, and to which is attached a label in Montagu's hand-writing, is not an lone, but a Bopyrus. Brebisson ("Crust. Departm. Calvados") states that lone thoracicus " se trouve sous les pierres baignees par la mer ; ' but we fear that he was misled by Latreille's incorrect reference of Oniscus c&ruleatus (Praniza) to the Oniscus thoracicus of " Montagus," in the " Encyclopedic Methodique." We cannot reconcile his description of the animal with the true lone. CllYPTOTIIIRIA. 257 TSOP 0 DA . B OP JfORMALIA, Genus-CRYPTOTHIRIA. Cryptotliir. DANA (1852). LiriojH'. RATHKE (1843, not Lirlope of Lesson. — Gr. Medusa^ 1839.) Liriopsis. SCHULTZE, Wiegm. Arch. 1859, p. 310. Cryptoniscus. FRITZ MULLEB MSS. Hemioniscus. BUCHIIOLZ. THE animals of this genus differ from those of most of the genera of Bopyridce in the nature of their habitats (being parasitic on crustaceans that are lower than themselves in the natural classification) as well as in their structure ; the supposed males, or at least the young, bearing a much stronger resemblance to the young than to the full-grown male Bopyri, whilst the females appear to be entirely destitute of antennae, legs, branchial lobes, or other appendages. The supposed males and young are very minute, oval or elongate in form, convex, with the head and segments of the body and tail distinct, the former semicircular, provided with two eyes and four antennae, of which the anterior pair are very minute and slender, whilst the posterior pair are greatly elongated, being about half the entire length of the animal, composed of three or four moderately long basal joints, followed by a multi- articulate flagellum, of which the first articulus is the largest. The parts of the mouth have not been deter- mined, but they appear to be covered by a large square pair of plates (maxillipeds), of which the lower margin is serrated, or possibly only fringed with hairs. Each of the VOL. II. S 258 BOPYRIDjE. seven segments of the body is furnished with a pair of legs, affixed within the lateral margin on the underside; they are more elongated than in the Bopyri, and more or less hooked for prehension ; they are nearly uniform in size, the anterior pair being, however, the strongest, and the posterior the longest and most slender in one or more of the species.* Each of the segments of the tail is furnished on the underside with a pair of branchial appendages differing in form in the different species, but very strongly fringed with long setae. The female is a large inert mass of animal matter, destitute of appendages, and is affixed to the animal on which it is parasitic. It is divided into two portions, the one consisting, according to Lilljeborg, of four distinct segments, which supports the organ or tube by which it adheres to its prey, whilst the hind part of the body consists of a simple sac for holding the eggs. Writing to us on this genus, Dr. Fritz Miiller says, " Changes in form not less important than those observed in the Hyperina are to be seen also in the Bopyrida. I have already published the description of a new genus of this family, Entoniscus, whose retrograde metamor- phosis proceeds much farther than that of Bopyrus (see p. 265 post, note f). I have since found another species of the same genus living in different Brachyura (Xantho, &c.), and a second genus (Cryptoniscus, F. Miiller, MSS.), almost unrecognizable when adult ; indeed the female of it then resembles Planaria lactea rather than an Isopod. It is, moreover, very interesting in its habits ; it does not take its sustenance directly from the little Pagurus, on whom it is fixed, but from the roots of the In the species observed by Lilljeborg and Fritz Miiller (Entoniscus Galatkece ) the young have only six pairs of legs. CRYPTOTHIRIA. 259 Sacculina purpurea, which it kills, but whose roots, not- withstanding, continue to grow and frequently attain an extraordinary development. " In the genuine Bopyridae all the feet are of the same form, while in Entoniscus and Cryptoniscus the sixth (or last) pair show a very different structure." The larva of Cryptoniscus has the sixth pair of pereiopoda long, slender, and styliform. That of Entoniscus has the same limbs long and slender, with large and powerful prehensile claws. M. Hesse, in his Fourth Memoir on Rare or New Crustacea of the coasts of France, " Ann. des Sci. Nat. 1864, ser. v. vol. ii. p. 281," described and figured the female of Peltogaster tau, which he found on Paguri, together with its monoculoid-cirriped-like embryo. More recently (in his Tenth Memoir, Ibid. vol. vi. p. 321, 1866) he gives an elaborate account of P. paguri, in which he describes an animal, of which he had only taken a single specimen on a Pagurus, and which he considers, without sufficient proof, as the male, together with the female, and the young animal in its earliest stage of develop- ment. The earliest form of the larva he describes as resembling that of the Entomostracous Crustacea, and states that, as in all of the suctorial crustaceans, the larva has three pairs of appendages. He also describes it as having lateral processes on each side of the anterior margin of the head, and that these processes are im- mature antennas, thus proving its relationship with the Cirripedes, and leading us to infer that the parent animal which he figures as the female is bisexual, and that his supposed male has no connection with the female, but must be considered as that of a Bopyroid crustacean, possibly of a Cryptothiria in an advanced stage of s 260 development. Lilljeborg, Rathke, and Buchholz, on the contrary, describe and figure the larva of the present genus as we find it to exist among the Bopyroid Crustacea generally, and which is a modification of the typical Isopod. , INTERMEDIATE PRANIZA-LIKE FORM OF THE FEMALE OF C. BALANI, FROM BUCHHOLZ. — (See p. 271.) CRYPTOT1IIRIA PYGMJEA. ISOPODA. NORMAL1A. 261 EOPYRIDJR. CRYPTOTH1RIA PYGJNLEA.* Specific character. — Supposed Male. -- Elongate-ovate, posteriorly at- tenuated, convex above, concave beneath. Cephalon rather longer than the following segment. Anterior pair of pereiopoda strongest ; posterior pair of pereiopoda long and slender. Sixth or terminal segment of the tail forming a minute plate, covering the base of the hind pleopoda. Female with the body divided into two portions, the anterior composed of the head and three following segments, connected by means of a constriction ' The woodcut at the head of this article represents the male of C. pyymcea, and the extremity of its body highly magnified, from specimens furnished by the Rev. A. M. Norman. The female C. pyymcea, (copied from LiUjeborg) is the upper left-hand figure ; Rathke's figure of the young C. pyymcea (which, if the form of the antennae be correct, is undoubtedly a male of mature form) is copied in the upper right-hand figure ; whilst the lower right-hand figure is copied from Lilljeborg's figure representing the side view of the young of L. pygmcea. 262 BOPYRIM. or neck with the hind part or matrix, which is exarticulate or sacciform, kidney-shaped, destitute of appendages. Length of male, one-tenth of inch ; female, (?) Liriope pyymcea. H. RATHKE, Reise Bemerk. aus Skand. in Neust. Schr. Naturf. Ges. Danzig, torn. 2, p. 105—110 (1841). Nova Acta Acad. Cses. Leop. Nat. Curios, torn. 20, p. 244, pi. 1, figs. 8—12. LILLJEBORG, Liriope et Peltogaster, in Nova Acta Reg. Soc. Upsal. ser. 3, vol. iii. p.. 6, pi. 1, figs. 1—23 (1859). Suppl. to ditto in ditto, pi. 6, figs. 1, 2 (1860). Oniscus squiUifonnis. PALLAS, Spec. Zool. fasc. 9, p. 50 ? CAVOLINI, Mernoria sulla Generaz. dei Pisci e dei Granchi, transl. Erzeugung derFische u.d. Krebse, pp.164, 165, pi. 2, figs. 18 m, n, r, r. THE history of this species has been remarkable, nor can it yet be regarded as free from difficulties. Cavolini, as quoted above, first described and figured two different crustaceous animals (one of which he doubtingly referred to the Oniscus squilliformis of Pallas) which he had found parasitic within a sac attached to the tail of a crab belonging to the genus Portunus or Carcinus. In 1839, Rathke found in the Norwegian Sea, upon the bodies of Carcinus mcenas and Pagurus Bernhardus, two species of vermiform parasites, which he regarded as belonging to the Entozoaria (but which have since been proved, by their transformations, to belong to the Cirrhipeda), and which have subsequently been described under the names of Pachybdella Carcini * and Peltogaster Paguri. Within the body of the latter of these two parasites Rathke found eight minute crustaceans, which he con- sidered had been devoured by the Peltogaster, and which he described under the name of Liriope pygm&a, referring them to the order Amphipoda, unaware that the generic ~ Professor Bell, in his volume on the Stalk-eyed Crustacea, p. 108, de- scribes the female of this parasite (Packybdella carcini) as infesting Por- tunus marmoreus even to a greater extent than Carcinus mcenas. CRYPTOTHIRIA PYGM^EA. 263 name had been employed four years previously for a genus of Medusce, by Lesson. Steenstrup, in the " Oversigt ' of the Royal Danish Society for 1854 (pp. 145 — 148), considered that this minute Liriope, instead of having been devoured by the Peltogaster, was either a parasite upon it, or that it was its young state. Professor Schmidt having, however, shown that the young of the Peltogaster resembled that of the Cirripedes, Steenstrup (subsequently, op. cit. p. 214) abandoned his former opinion, leaving the ques- tion unsettled. In the " United States Exploring Expedition," Crust, p. 801, pi. 53 (1852), Dana described a new genus (which he unnaturally placed in the family Tanaida>), under the name of Cryptothir, remarking, as Steenstrup had done, that Rathke's Liriope was not an Amphipod, but in reality an Isopod crustacean. Steenstrup had, however, referred Liriope to the family Balanidce. Three or four specimens of the Crypto thir minutum were taken separately in as many individuals of the corallidomous barnacle, Creusia. In 1858 Lilljeborg found in the Norwegian Sea a Pagurus pubescens with a Peltogaster attached to its tail ; but the parasite appeared to be double, one portion being- filled with eggs, and which he consequently considered to be the single ovigerous sac of the parasite hanging sus- pended from the body, as is the case with the double egg- sac of the Cyclops, &c. But the fact that the Peltogaster was a suctorial animal, and not a mandibilated one (like the Cyclops), and that the egg-sac had motions inde- pendent of the Peltogaster, even after the latter had died, and the body of the Pagurus had putrefied, greatly per- plexed Lilljeborg. He then examined the sac and its con- tents more carefully, and discovered that the former was a distinct animal, parasitic upon the parasite, and that the 264 BOPYRID.E. young were totally unlike the Cirriped-formed larva) of the Peltogaster, and that they exactly resembled Rathke's Liriope ; thus proving that the body of the supposed Peltogaster of Rathke, in which the Liriopes were found, was, in fact, the superposed body of the second parasite, or, in other words, that the female of Liriope was now discovered, that Rathke's animals were the young of that female, that Dana's Cryptothir^ found upon a Balanus, \vas either the young or male of a closely-allied animal, and that Cavolini's parasite, found upon Portunus, was to be referred to the same group. As the minute and active Liriopes were found, both by Rathke and Lilljeborg, within the egg-sac of the parasitic female, the question arises (and is still undetermined) whether these little creatures are exclusively young males, or are the larvae- form of both sexes ? and whether the adult male does or does not retain its larva shape almost unaltered during the whole of its life ? Analogy with the stages of de- velopment of the Bopyrida, and especially with those of the following species, would lead us to adopt the opinion that in their earliest stages both sexes of this genus are alike in form, and that whilst the female gradually loses the articulated character, together with all the external appendages of the body, the male retains much of its larva condition. Such is the opinion of Lilljeborg, who has argued the question at considerable length, and such appears probable on taking into consideration the comparative characters of the young and adult males of Bopyrus squillarum (as represented in our figures in p. 218), of Gyge galathece (p. 225), and of lone thoracica (p. 254), and those exhibited in our several figures of the young or males of this species, given by Rathke and Lilljeborg copied as above, and our own as given in the cut at the head of this article. According to Lilljeborg, however, CRYPTOTHTRIA PYGM^A. 265 the youngest state of the animal has only six pairs of legs, the sixth being half as long again as the others, and terminated by a very slender elongated finger, whilst the five preceding pairs are of equal size, and sub- cheliferous.* Rathke, on the contrary, although he only figures four of the legs on one side of the body of his Liriope (the fourth being minute and slender), expressly states, in the description of his figures, that his detached figure of this hindmost leg represents the seventh, or posterior one. As it is impossible, however, to over- look the strong relationship which evidently exists between the Liriope and Enioniscus Porcellance^ elaborately de- ' Lilljeborg's statement seems fully confirmed by Fritz Mailer's description of the larva of Entoniscus Porcellance. + The female of this remarkable parasite resides within the body of a species of Porcellana, lying in a thin- walled sac between the liver, intestine, and heart of its host, the head being " destitute of eyes and antennae ; the thorax has become an irregular inarticulate sac, beset with enormous brood-laminae ; the long vermiform and extremely mobile abdomen has sword - shaped legs ; and swelling out above it in a globular form, as if in a hernial sac, the heart lies at the base of its first segment ! "' The young of this sin- gular parasite closely resembles that of Bopyrus and Liriope, being oblong- ovate and flattened in form, with one pair of antennae very short and thick, whilst the other pair is half the length of the body, and bent backwards. ' ' The five anterior segments of the thorax bear similar feet, terminated by a thickened ovate palm, and a slightly curved powerful claw. " The sixth pair of legs are only three -jointed, the last joint being elliptical. There is no seventh pair of legs. " The abdomen bears, first of all, four pairs of natatory feet, with a crescentiform basal joint, and a lancet-shaped terminal joint, furnished with strong bristles." The fifth abdominal pair of legs is a narrow and short appendage, without bristles, cleft into two unequal divisions ; and the terminal pair of appendages consist of a thick basal joint and two slender biarticulate terminal branches. The male somewhat resembles that of the Bopyridce. The body is elongate- obovate and regularly articulated, the head is trapezoid, with rounded angles extending considerably beyond the sides of the following segment. The only pair of antennae are short, inarticulate, flat, and quadrangular. The mouth forms a "triangular rostrum." "The six anterior thoracic segments bear feet reduced to nearly sessile inarticulate roundish lumps. The seventh seg- ment has no feet, but bears on each side, at the posterior margin, a wart-like process, and on this the genital orifice." The abdomen is considerably elongated and narrow, composed of six segments entirely destitute of appendages. f, 266 BOPYRID^E. scribed by Fritz M tiller (Archiv. f. Naturg. xxviii. p. 10, and Ann. Nat. Hist. 3 ser. x. p. 87, pi. 2), we are led to the conclusion that the animal we figure from our own drawing is a young male of this genus, and that in its full-grown state it may be somewhat modified in the form of its locomotive organs. The female of C. pygmcea is now, however, satisfac- torily known by the researches and figures of Lilljeborg. It consists of two separate portions in its adult ovigerous state, the anterior being convex and smooth on the upper side, and concave beneath, composed of four segments, of which the two central ones are the largest ; the first, or head properly so called, constituting an organ by which the animal affixes itself upon the Peltogaster. The hind part of the body is exarticulated, sac-like, kidney-shaped, and convex above, with a slit on its underside through which the young are expelled. There is not the slightest vestige of antennae, eyes, mouth-organs, prehensile or branchial legs. Our specimen of the supposed male was taken with the dredge off Guernsey by the Rev. A. M. Norman, not attached to any animal, but he found it in a bottle in which Crustacea, for the most part Amphiphods, had been put. CRYPTOTHIRIA BAJANI. I SO POD A. NORM ALIA. 267 BOPYRID^E. CRYPTOTHIRIA BALANI. Specific character. — Immature (?) Male. — Elongate-ovate, cephalon fur- nished beneath with two flat lobes, serrated on their posterior margins, mouth forming a conical process ; upper antennae very short, lower antennae nearly half the length of the animal, reflexed ; pereion with seven pairs of pereio- poda, first and second pairs with strong palms and hooked fingers, five pos- terior pairs slender and simple. Pleon with five pairs of branchial appen- dages, each composed of two lobes. Adult Female. — Forming a large inert seven-lobed mass, destitute of ex- serted antennas, jaws, legs, or branchial appendages. Length of the supposed male, about one line ; female, about one-quarter of an inch. Liriope balani. SPENCE BATE, Brit. Assoc. Report, 1860, p. 225. Hemioniscus balani. BUCHHOLZ, in Siebold and Kolliker, Zeitschr. f. Wissensch. Zool. xvi. 3 h. p. 303 (September, 1866). Balanus balanoides, male. GOODSIR, H. S., on the Sexes of the Cirri - peds, &c., Edin. New Phil. Journal, p. 88, v. 35 (1843). Ann. d. Sci. Nat. 3 ser. Zool. t. 1. " pi. 15 c. THE first notice we possess of this animal is that given 268 BOPYRLDJI. by Mr. Henry Goodsir in the " Edinburgh New Philoso- phical Journal for 1843," where he erroneously described the female, or the animal represented in our right-hand figure, as the male of the cirriped (Balanus balanoides), and the animal, copied in our left-hand figure, as being parasitic upon that supposed male. About the time of the publication of a memoir in the "Annals of Natural History," " On the Development of the Cirripeds," in 1851, our attention was drawn to a fleshy mass of material that we found attached to the base of the animal of the Balanus balanoides, lying within the shell. This we first took to be the ovisac of the Balanus, because we found it always full of ova, which we then thought were the ova of the Balanus in one particular stage. In this we thought we were confirmed by the fact that we never found the ova of Balanus in the condi- tion most familiar to us in any of those specimens where these ova were found. A drawing of the mass, which DEVELOPMENT OF LARVA OP CRYPTOTHIRIA BALANI. we submitted to Mr. Darwin, induced him to suggest it as being the parasite that Mr. Goodsir described as the male of the cirriped ; and an examination of the article " On the Sexes of the Cirripeds," clearly showed us that CRYPTOTIIIRIA BALANT. 269 Mr. Goodsir's figures were more or less perfect repre- sentations of the mass that we had observed. The young, which we have frequently taken in an incomplete stage, are developed as in true Isopoda ; and the earliest larval condition, as figured by Goodsir and Rathke, shows that the animal is, both in its develop- ment and parasitic habit, closely allied to the Bopyroid Crustacea. The animal represented in the middle of our wood- cut, which we consider to be the male, corresponds, so far as the head and anterior segments of the body are concerned, with that which Mr. Goodsir has figured as being the anterior segments of his supposed male, and, if Mr. Goodsir's dissections be true, appears to offer a very considerable evidence of the near relation of the two animals. But we were inclined to think that Mr. Goodsir's figures, 1 — 3 in pi. 3, which he gives as the concealed cephalic portion of what he calls the male of the Balanus, and the entire dorsal view of the same animal given in pi. 4, fig. 10, were taken, the former from the real male, and the latter from the female, Liriope.* Though frequently having taken the females in con- nection with the Balanus, and these also charged with ova in various stages, we have never taken the male asso- ciated with the female, as is almost invariably the case with the other genera of the Eopijridce. Tn this species In the elaborate memoir of Dr. Buchholz above referred to, published last September, the learned author has arrived at an opposite conclusion rela- tive to the true condition of our supposed male, which he has carefully figured and described as the larva-forni of the species, and which, in certain indi- viduals at least, becomes developed into the female, the fully developed con- dition of the male being still unknown. This observation completely supports the correctness of Goodsir's statement, that his figures 1-3 represent the anterior articulated part of the animal of which a dorsal view is given in his figure 10, in which, however, the 'articulated portion is concealed by the swollen front of the second division of the body. 270 BOPYRID^. we have always found that which we consider as the male animal to be free, and roaming distantly from its supposed mate. The cirriped which it infests (Balanus balanoides) is a gregarious species, and lives upon the rocky shore between the tidal marks, and we have fre- quently seen, on breaking off a mass of the Balani, the little red Crustacea run away, and the paucity of the males that we observed in comparison with that of the females, has induced us to consider that the male wanders about from one cirriped to another. The animal is of a red- brown colour, and is an active little creature. The female, in its adult state, is a large inert inarticulate mass, destitute of antennae, mandibles, or foot-jaws, legs or branchial appendages, with the body dilated on each side into three large rounded or conical lobes, the tail itself forming a terminal lobe similar to the others. In Dr. Buchholz's specimen the body (probably from having been immersed in spirits) was of a broader and rounder form than in our figure, with the lobes more conical and more regularly radiating, giving the animal more of a star-like appearance. It is furnished with a short mouth or sucker, by which it affixes itself to its prey. The young animal, as described by Buchholz, or the male as suggested above, is elongate (more ovate in Buchholz's figure than in our own), with the head as wide as the following segment, which, as well as the remaining segments of the body (and also of the tail, according to Buchholz), have the lateral margin deflexed, with its posterior margin serrated. The mouth consists of a conical process, protected above by two flattened plates, of which the posterior margin is serrated. The minute pair of upper antennae are affixed at the sides of these appendages, and consist of a strong basal joint, thickly fringed with long seta?, and a terminal articulated CRYPTOTHIRIA BALANI. 271 flagellum. The lower antennae are strong and elongated, consisting of four large basal joints, gradually diminishing in length and thickness, and terminated by an articulated flagellum. The seven segments of the body are furnished with the same number of legs, of which the first and second pairs are shorter and more robust than the rest, and terminated by an oval palm and a movable finger.* The remaining five pairs of legs are long and slender, the seventh or last pair especially being longer than the rest. The tail is obconical, the five anterior segments being furnished on the underside with as many pairs of branchial appendages, each consisting of an oblong basal piece, bearing two terminal branches, of which the inner is long and conical, and the outer shorter and pointed. Buchholz, on the con trary, represents them as consisting of a dilated basal sub triangular joint, terminated by two oval or suboval plates, strongly fringed at the posterior margin with long setae. The transformations which this minute active pedi- gerous animal undergoes in assuming the adult female form have been carefully observed and figured by Dr. Buchholz. In the earliest of these changes we observe a striking analogy with the form of the female Anceus, the three posterior segments of the body coalescing, losing their articulated character, and swelling out into a large mass, in which the segments are only indicated by lateral impressions ; those of the tail, however, remain- ing distinct."!* In the following stage the tail is entirely absorbed, forming a terminal exarticulate conical mass, continuous with the lobes of the body, but with the * In our specimen we could not determine the precise form of the first pair of legs, and which are not quite correctly given in our figure, t See Vignette in page 2 CO. 272 BOPYRnm head and four anterior segments and legs of the body still distinct. In the next stage the great terminal mass, forming seven rounded lobes, is much increased in size, the fourth segment of the body has become absorbed,* and a large membranous dilatation also appears on the underside of the general mass. In the final stage all distinct traces of the head and three anterior segments appear to be lost, and the animal reduced to the inert mass represented in the right-hand figure of the wood- cut at the head of this article. According to Buchholz, however, the full-grown female still retains the antennas and fore pair of legs, although immersed in the fore portion of the sac-tike envelope of the rest of the body (see his fig. 4 in pi. xvii. " Vorderkorper ernes erwachsenen inclividuums von dem Sacke abgetrennt "). It is from this circumstance, as well as from a considera- tion of the character and number of the legs and branchial appendages of the immature state that Dr. Buchholz was led to separate this animal from Liriope as described by Lilljeborg, under the name of Hemioniscus. Until, however, the males of both species are positively determined, we consider it more advisable to retain them both in one genus. The animal in this state exhibits a striking analogy to the adult gravid female of the Chigoe (Pulex penetrans). CYMOTHOID^. 273 THE second subtribe of the Parasitical Normal group of the Isopoda contains all those species in which the sexes are not materially unlike each other, the males being generally nearly as large as, or larger than, the females, with the dermal tissue hard and crustaceous, the pereiopoda well developed, the oral organs formed for mastication, the mandibles being horny, having the terminal half narrowed and curved inwardly, with the apex formed for gnawing, the base also furnished with a triarticulate appendage. The pleon is terminated by a large flat crustaceous plate representing the sixth seg- ment, bearing near its base at each side a pair of elongate flattened lobes (uropoda) arising from a dilated base. These animals compose the family of Cymothoadiens of Milne Edwards,* which he has divided into three tribes corresponding with our families — namely, 1. CYMO- THOADIENS RAVISSEURS or SEROLID.E ; 2. C. ERRANS or JEoiDJE ; and 3. C. PARASITES or CYMOTHOID^. The first of these tribes consists of the singular genus Serolis, the species of which are thought by many to offer a very strong resemblance to the Trilobites. They are all natives of the Ocean surrounding South America, and are distinguished by their flat circular form with moderately long antennae, and with the first or the first and second pairs of legs strong and cheliferous, whilst the remainder are slender and fitted for walking. The second tribe corresponds with our family * The Cymothoadaa of Dr. Leach's article in the " Dictionnaire des Sciences naturelles " was still more extensive, as he introduced into it not only the groups admitted by M. Milne Edwards, but also our Sphceromidce and the genus Limnoria. VOL. II, T 274 ISOPODA. whilst the third tribe, C. parasites, forms our restricted family CYMOTHOID^E, the species of which are parasitic on fishes, all their legs being alike in form and strongly hooked for prehension, they are all, as well as the antennae, short, and the latter are always inserted on the underside of the head, beneath a prolongation of the forehead, and the body is of a less firm consistence than in the JEgidw, thus approaching the Bopyridce. The species are numerous, but chiefly inhabitants of Tropical Seas ; some few are, however, known to inhabit more temperate climes, but no specimen has hitherto been satisfactorily determined as having been found in our own seas, although Cymothoa CEstrum* is introduced by h Cymothoa, Fabricius, is distinguished from the other genera of this tribe or family by having all the segments of the pleon distinct and movable, the pi eon itself considerably narrower than the terminal portion of the pereion, the last segment wider than long, and the legs tolerably strong and subche- liferous. Cymothoa CEstrum* is distinguished from the other species of the genus by having the anterior margin of the cephalon advanced and bent down between the inner antennae, which are inserted widely apart, the first segment of the body very large and advanced beyond the head on each side, and by the lower edge of the bases of the fourth pair of legs armed with a strong tooth. This species is found in the Atlantic Ocean and in the Seas of both Indies. It attacks fish, and makes occasionally large wounds sufficient to cause the death of the individuals attacked. 1 Oniscus CEstrum, LINN. Syst. Nat. pp. 1059, no. 2, Faun. Suec. no. 2053. Mus. Adolph. Frid. 89. FABRICIUS, Syst. Ent. p. 294. Sp. Ins. i. p. 375, no. 4. PALLAS, Spic. Zool., fasc. 9, p. 74, tab. 4, fig. 13, A. B. Cymothoa CEstrum, LEACH, Edinburgh Enc. vii. pp. 405 and 433. Enc. Brit. Suppl. 1, p. 428. Trans. Linn. Soc. xi. p. 372. Diet. Sc. Nat. t. 12, p. 353. SAMOUELLE, Ent. Compend. p. 109. DES- MAREST, Cons. Crust. 309, pi. 47, figs. 6, 7. MILNE EEWARDS, Hist. N. Crust. 3, 269. RegneAn. (Crochard Edit.), Crust. pl.65,f. 1. Asellus CEstrum. OLIVIER, Enc. Meth. 4, 253. . 275 Samouelle into his work on British Insects, without, how- ever, any locality being subjoined, and, as it is omitted by Mr. White in his Catalogues of the British Crustacea, it seems evident that no tradition exists in the British Museum (of which Mr. Samouelle was also an officer) to warrant its introduction. As it is possible, however, that it or some other of these fish-parasites may occur, we have introduced the above family characters. In the second tribe of Milne Edwards, forming our Fam.— JEGID.E, The species are amongst the largest known Isopods, and are distinguished by having their antennae fixed in front of the head, the basal joint of the anterior pair being very broad and flat, and uniting together to form a margin in front of the head, not being concealed beneath the advanced cephalon ; the outer-foot jaws have the basal joints moderately dilated, with three or four terminal joints, which are rarely palpiform ; the pereiopoda are of moderate length, the anterior pair being generally the strongest and fitted for prehension, being terminated by a robust curved finger, acute at the tip; whilst the hind legs are gradually elongated and fitted for walking. The five segments of the pleon are very short, each on its underside supporting a pair of double foliaceous plates for respiration, whilst the last segment of the pleon is large and flat, and bears on each side near the base a pair of flat appendages, scales arising from a basal joint, of which the inner angle is sometimes produced into a long style. 276 TSOPODA. NORM ALT A Genus — MGA. (Leach). Generic character. The three anterior pairs of legs in this genus are strong and terminated by a powerful hook-like finger, whilst the four posterior pairs are longer and more slender, with a but slightly curved terminal finger, so as to fit them for progression ; the short inner antennae have the basal joints very broad and flattened, occupying the front margin of the head. THE species of this genus are of large size. They are oval, moderately convex, with most of the segments marked transversely with a slight ridge. The coxae or first joint of the legs (epimeral pieces of Milne Edwards) are formed so as to appear as part of the dorsal surface. The eyes are of large size and oval, extending consider- ably backwards at the sides. The outer antennae are affixed beneath the fore margin of the head, and are separated from each other by an ele- vated scutcheon-like piece or labrum ; they are composed of five or six strong basal joints gradually increasing in length, but diminishing in thickness, and are terminated by a flagellum composed of about a dozen articulations. The mandibles are strong, with the apical portion angu- lated and bifid ; they are furnished with a prominent three- jointed palpiform appendage arising near the external base. The outer-foot jaws are rather valve-shaped, with the basal joint strong and elongated, bearing a triangular 277 lobe on its external base; the second joint is produced internally, and the three terminal joints are short, the last being armed with several minute teeth; the outer pair of maxillae are curved and slender, terminated by two denticulated pieces, and the inner pair of maxillae are still more slender, with several minute reflexed teeth at the tip.* The pleon is nearly as wide at the base as the terminal segment of the pereion ; the four anterior segments are of equal size and short, with the lateral margins strongly produced posteriorly into an acute angle ; the fifth segment is shorter than either of the preceding, whilst the terminal segment is large, flat, conical, or semiovate or semicircular, often with one or two central ridges ; each of the five basal segments bears on its underside two pairs of delicate membranous ciliated branchial plates, all of nearly equal size, and each pair arising from a transverse basal piece. They do not cover the whole of the underside of the tail. The terminal segment also carries on each side a pair of flattened appendages that do not reach beyond the posterior extremity of the pleon. * Our description of the parts of the mouth is made from JEga bicarinata. In Milne Edwards's figures of details taken from JEya eniaryinata, the diffe- rent organs appear to be less denticulated at the tips. 278 ISOPODA. NOR MALI A. .EGA BICARINATA. Specific character. Animal depressed, terminal segment of the pleon wide at its extremity, bearing on its upper side two diverging carinatecl lines, which terminate at the posterior angles, the intervening space nearly straight or slightly emarginate. Uropoda with the inner division larger than the outer, truncated at the inner extremity. Length, lg inch. JEga, bicarinata. LEACH, Dictionn. Sci. Nat. xii. p. 349. DESMAREST, Cons. Crust, p. 305. MILNE EDWARDS, Crust, iii. p. 241. CUVIER, Regne An. (Edit. Crochard), Crust, t. 67, f. 2. RATHKE, in Nov. Acta Cses. Leop. Nat. Curios, vol. xx. pi. 6, f. 1 — 12. WHITE, B. M. Cat. Brit. Crust, p. 79. Pop. Hist. Brit. Crust, p. 251, pi. xiv. f. 5. GOSSE, Man. Mar. Zool. 1, fig. 232. THIS is one of the largest species of known Isopods, some individuals measuring about one inch and a half in length. It is at once distinguished by the two elevated divergent lines on the terminal segment of the tail and by .EGA BICARINATA. 279 the larger size of the inner division of the appendages at the sides of that part of the body, which is, moreover, somewhat truncated at its inner extremity, whilst its outer margin has a slight emargination near its extremity. The eyes are wide apart and occupy the posterior angles of the head. The upper antennae are scarcely longer than half the width of the head ; the basal joint is large, flat, and square, the second joint produced along its anterior mar- gin so as partially to conceal the base of the third joint (when seen from beneath), which is slender and succeeded by a very short flagellum, consisting of five or six arti- culi ; the lower antennae are about as long as the width of the head, and have three short thick basal joints ; the fourth is longer than the third, and the fifth nearly as long as the fourth, but more slender, and is followed by a flagellum, consisting of twelve articuli ; these organs are separated at the base by a scutellum-shaped labrum, arising from a transverse keel or epistome. At the sides of each segment of the pereion the coxse of the legs are developed as parts of the dorsal surface (epimera), and have their outer portion raised and curved so as to form elevated spines overlapping each other ; the segments themselves are marked across the middle, or nearer the base, with a raised line ; the four anterior segments of the pereion are of equal size. The surface of the pereion is seen, under a strong magnifying power, to be entirely covered with very minute circular punctures, amongst which larger and more irregularly shaped ones are dis- posed without order. Our drawing is made from Dr. Leach's original type specimen in the British Museum, to which his own ma- nuscript name is still attached. In this specimen the extremity of the tail is formed precisely as represented 280 MGIDM. in our figure. Dr. Leach, however, in his description, says, " extremite presque tronquee, echancree." The species inhabits the Mediterranean, and is also found not unfrequently on our coasts. Specimens from St. Leonards are in the Hopeian collection at Oxford. We have also obtained it by trawling in Plymouth Harbour at the beginning of February, and have received it from the Rev. A. M. Norman, who has taken it on the coast of Durham. The Oxford Museum also possesses a small specimen labelled as having been taken at Plymouth, which \vas considered by Mr. Hope as a distinct species (the MS. name of " Spilota, Hope," in the handwriting of the donor himself, being attached to it), it being dotted all over with small brown spots, arranged at equal distances apart, so that there are about a dozen occurring next the posterior margin of each segment. TIUDENS. 281 1SOPODA. NORM ALIA. TRIDENS. Specific character. Differs from ^Ega bicarinata in having the last seg- ment of the tail furnished with three carinae, each of which is produced into a small point beyond the posterior margin of the segment, the space between the two lateral teeth being emarginate ; eyes large, having only a small space between them in the centre of the anterior margin ; inner plate of the caudal appendages larger than the outer and truncated at its extremity. Length, an inch and a half. tridens. LEACH, Trans. Linn. Soc. xi. p. 370. Die. Sc. Nat. xii. p. 349. DESMAREST, Crust, p. 305. MILNE EDWARDS, Crust, iii. p. 242. WHITE, B. M. Cat. Brit. Crust. p. 80. Pop. Hist. Brit. Crust, p. 251. Var. ? with central spine of tail obsolete. JEya monophthalma var. minor. JOHNSTON, in London's Mag. Nat. Hist. vii. p. 233, fig. C. (?) THIS species is closely allied to &ga bicarinata, but is distinguished by the three carinse on the terminal segment of the tail, the two lateral ones being the strongest, and each terminating in a small tooth on the posterior edge of 282 the tail, which is emarginate. The body is elongate-ovate, and convex, the eyes large and nearly meeting on the crown ; the upper pair of antennae are not longer than the head, with aflagellum composed of about twelve articula- tions, the two basal joints very broad (the second obliquely emarginate), with the nagellum affixed on its hinder angle. The coxae of the legs attached to the anterior segments of the pereion are sub quadrate and marked with straight elevated ridges; these are represented in our upper right- hand figure as seen on the underside of the body, show- ing the base of the three fore legs on the left side. The branchial plates on the underside of the body (as represented in our lower left-hand figure) scarcely ex- tend beyond the middle of the terminal segment ; they are all of nearly equal size, the upper or outer pair not covering the whole or even the following pair. The lateral appendages also, when folded up, scarcely extend beyond the lateral margins of the terminal segment, the truncated extremity of each inner division uniting and leaving a triangular space uncovered at the extremity of the tail ; the outer division of these lateral appendages is considerably smaller than the inner, and elongate- ovate in form, pointed at the tip, with the outer edge armed with spines arranged in transverse rows. The typical specimen of this species described by Leach was contained in Sowerby's collection from Scot- land, and Mr. Gregor has sent it to us from the Moray Frith, and there are others now in the British Museum from Belfast, presented by Colonel Portlock. The late Mr. "W. Thompson, of Belfast, also obtained it from Belfast Market, where it was found among Car- rickfergus oysters, at the end of March, 1839, and also from a cod-fish brought to the same market in February, 1841. ISOPODA. NORM All A. PSORA. 283 .EGA PSORA. Specific character. Oval and convex, coxae marked with two oblique lines ; those attached to the four anterior segments square, those to the three poste- rior segments subtriangular and distant from each other; terminal segment of the pleon triangular, smooth on its upper side, with the lateral margin slightly dilated ; inner plate of the lateral appendages emarginate near the extremity of its outer edge. Length, 1^ to nearly 2 inches. Oniscus psora, emarginala. PENNANT, Brit. Zool. vol. iv., pi. 18, f. 1, 3777 (certe). LEACH, Dictionn. Sci. Nat. xii. p. 349. Trans. Linn. Soc. xi. p. 370. Suppl. Enc. Brit. 1, 428, pi. 22. SAMOUELLE, Ent. Compend. p. 109. DESMAKEST, Crust, p. 305, pi. 47, f. 4, 5. MILNE EDWARDS, Crust, iii., p. 240. CUVIER, Regne An. (Ed.Crochard), Crust, pi. 67, f. 1. THIS species is distinguished at once by the somewhat triangular form of the terminal segment of the tail, which 284 is flat on its upper surface and destitute of the carinse observable in the other British species ; its sides are rather dilated at the base and somewhat recurved. The animal is oval and convex; the eyes large and lateral, with many hexagonal facets ; those, however, of the external margin have their outer edge circular (a peculiarity now ascertained to occur in the hexagonal structure of the c> hive bee, which has lately been the cause of considerable discussion among Entomologists). In our figure, 0, the third or right-hand row of facets is the external one. The upper antennae are short, with a ten-jointed flagel- lum, whilst the lower ones have the same part formed of about eighteen articulations. The palpiform appendage of the mandible is very slender and terminated by a short thin and curved hook-like joint. The three an- terior pairs of legs are strong and terminated by power- ful hooked fingers ; the middle joints in the first pair are very short, but in the third pair the second and third joints are armed with small conical tubercles; the four posterior pairs of legs are longer and more slender, the under edge of the terminal joints being spinose, the spines being set in transverse rows. The lateral appen- dages of the tail are narrow and of nearly equal size, the inner plate of each pair being strongly emarginate on its outer margin near the extremity, which is ciliated. In one sex these organs are accompanied on the inner edge by an elongated conical horny plate, represented in our middle left-hand figure.* Although the species was introduced by Samouelle into his work on British species (no locality, however, : In our principal figure of this species the articulation at the base of this narrow plate has been accidentally omitted, giving to the fifth segment of the tail the appearance of being produced on each side of the terminal joint into a long narrow point. PSORA. 285 being given), it is omitted by Mr. A. White from his Catalogue of British Crustacea. Dr. Leach (the chief authority for Samouelle's work), indeed, stated in his description of the species "localiteinconnue" (a specimen has, however, since been received by the British Museum from Iceland, from Mr. Drewsen), so that, except for the unnecessary doubt expressed by Leach in his refe- rence to Pennant's Oniscus psora* there is no recorded authority for its insertion in the British list. We are enabled, however, to introduce it unquestionably on the faith of a fine specimen in the Bell collection (now at Oxford, obtained at Scarborough by Mr. Bean, by whom it was presented, with other interesting species from that locality, to Professor Bell). This specimen has supplied the figures at the head of this description. The Hope collection also possesses a specimen from Nova Scotia, and we have received it recently from Mr. Gregor, who dredged it in the Moray Frith. * Although unquestionably this is the On. psora of Pennant, it is doubtful whether it be identical with the species so named by previous authors. 286 ISOPODA. NORM ALIA. MONOPHTHALMA. Specific character. Oval, convex, eyes very large, uniting dorsally, ex- tending obliquely backwards, the anterior margin of the first segment of the pereion being deeply incised on each side for their reception, terminal segment of the pleon flat, nearly semicircular, with a central carina terminating in a point. Length, 2| inches. ^Eya monophthalma. JOHNSTON, in London's Mag. Nat. Hist. vii. p. 233, f. 43. Rocinela monophthalma, MILNE EDWARDS, Crust, iii. p. 244. WHITE, B. M. Cat. Brit. Crust, p. 80. Pop. Hist. Brit. Crust, p. 252, pi. xiv. f. 7. GOSSE, Man. Mar. Zool. 1, fig. 233. THE animal is oval, of a pale brown colour, approach- ing to fleshy red, and when alive tinged with purple, dotted all over with numerous punctures. The upper antennae are very short, the two basal joints much dilated, forming together a broad movable plate ; the flagellum is setaceous, the lower antennas more than twice the length of the superior, the three basal joints short and unequal, the flagellum multiarticulate. The head is almost entirely occupied by the large oblong eyes, which MGA. MONOPHTHALMA. 287 coalesce dorsally and centrally ; they are reticulated and extend obliquely backwards, leaving a small point pro- jecting anteriorly between the base of the upper antennae and a small central triangular space behind. The inferior antennae are separated at the base by a small oblong concave plate or labrum. The seven segments of the body are nearly equal in size, marked with a faint line across the middle ; their sides are furnished with strong cox£e pointed posteriorly, and with two slight ridges down the middle. The first three pairs of legs are directed forwards ; they are robust, and furnished with strong curved claw-like fingers ; the four posterior pairs of legs are longer and much more slender, with the joints nearly equal and spinose, terminated by curved fingers. The tail is formed of six segments, of which the five first are short and equal, and the terminal one broad, oblong, roughish, depressed, with a strong keel down the centre ending in a short mucro ; the margins of these segments are minutely spinose ; on each side of the ter- minal segment is a pair of foliaceous plates articulated to a movable, acutely pointed, somewhat triangular pro- cess ; the inner plate is wedge-shaped and the outer one oblong ; both are densely ciliated round the edge. Dr. Johnston, whose detailed description is slightly abridged above, adds that this species swims with rapidity by the aid of its " caudal fins," and when it comes in contact with a solid body it clasps against it and adheres tenaciously. His specimens were taken adhering to large cod-fish, of which it is probable they are the " pedicular parasites ;" but, unlike some of their race, they appear to be very rare, at least in Berwick Bay, as he could only procure three individuals, and the fishermen had never observed them before. Dr. Johnston also described and figured as a variety of 288 JEGIDM. the other sex a smaller specimen (l| inch long), having the two basal joints of the upper antennas not dispro- portionably enlarged, and the last large segment of the tail emarginate-truncate, with a shallow furrow down the centre, and two obtuse raised keels at its sides. In other respects no difference appeared to exist. Except that the eyes in the figure of this smaller individual are represented as being of the same size as in the larger ones (uniting in the centre of the forehead), we should have referred it to Dr. Leach's j&ga bicarinata, or more probably to sE. tridens, with the central tooth of the tail plate worn away (the eyes being large, as in that species). Dr. Johnston, however, regarded it as belonging to the same species as the larger individuals, and probably the male of it, considering the dilatation of the basal joints of the upper antennae as a sexual character, or one de- pendent on age (and of insufficient value, therefore, to be ranked among the characters which are seized upon to divide tribes and families from each other), and also that the conformation of the terminal segment of the tail is not sufficient to discriminate species, as Dr. Leach seems to have believed, "for his specific characters em- brace no other part," at least in the species of JRga. Unfortunately the comparative rarity of these parasites does not yet allow us to determine this point. The individual of this species described by our late friend Dr. George Johnston was taken in Berwick Bay on a cod-fish, and is preserved in the British Museum, which also contains another specimen from the Northum- berland coast, presented by Mr. R. House. There are also British specimens of unnoticed locality in the Hopeian collection ; and we have received them from Shetland, from the Rev. A. M. Norman, who also records it from the Moray Frith. ROCINELA. 289 ISOPODA. NORM A LI A. Genus— ROCINELA. (Leach.} Generic character. Eyes very large and convex, converging anteriorly and nearly uniting in the middle of the forehead, which is produced into a conical point concealing the base of the upper antennae ; first and second joints of the latter cylindrical and much more slender than those of the lower antennae, which are nearly one-third of the length of the body. • As our generic and specific descriptions are made from Dr. Leach's original type of R. Danmoniensis (the only species which he inserted in the genus), we are able to ascertain that M. Milne Edwards has misconceived Leach's views (which is not indeed surprising, as the very short and unsatisfactory descriptions given by the latter would scarcely afford a definite idea of its characters). We consequently find that the genus thus named in M. Milne Edwards's great work consists of species of ^Ega, with the eyes confluent and the basal joints of the upper antennae rather more slender than in the typical JEgae ; but when we take into consideration, that the front of the head in Leach's type is produced into an obtuse conical point projecting over the base of the upper an- tennae, which are much more slender than the base of the lower antennae, the latter being also more than one-fourth of the length of the entire animal ; that the pleon is as wide as the pereion, the anterior segment being, however, very short, and abbreviated at the sides, which neverthe- less terminate in an acute point ; and that the three fol- VOL. II. U 290 lowing joints of the pleon are large and broad, the posterior lateral angles being produced into a curved and acute point, — we shall be convinced that Rocinela Danmo- niensis is the type of a distinct genus, and that ^Ega monophthalma of Johnston, which M. Milne Edwards, followed by Mr. A. White, introduces into the genus Rocinela on account of the large size of the eyes, ought to be referred to the genus JEya. This opinion is confirmed by the descriptions of the mouth-organs given by M. Milne Edwards in the Crochard edition of the " Regne Animal" of the species which he terms Rocinela ophthalmica (giving erroneously Leach as the author of the species), which prove that that species is in fact an -ZEga, differing only from jffiga emarginata in the apparent soldering together of the two terminal joints of the foot-jaws. ROCINELA DANMONIENSIS. 291 ISOPODA. NORM All A. ROCTNELA DANMONIENSIS. Specific character. Elongate-ovate ; eyes converging anteriorly, large, nearly joining dorsally ; basal joints of the upper antenna subcylin- drical ; coxa (especially of the three posterior pairs of pereiopoda) prominent, elongate -ovate, and pointed ; second, third, and fourth segments of the pleon sickle-shaped and laterally produced. Length, one inch. Rocinela Danmoniensis. LEACH, Diet. Sci. Nat. xii. p. 349. DESMAREST, Crust, p. 304. MILNE EDWARDS, Crust, iii. p. 244. WHITE, Cat. Brit. Crust, p. 80. Pop. Hist. Brit. Crust, p. 352. THIS species has hitherto been known only by Dr. Leach's original typical specimen taken half a century ago in Plymouth Sound, preserved in the British Museum, which has supplied the materials for the figures given at the head of this description. It was described by Leach as being "en si mauvais etat qu'il est impossible d'en V Z 292 JEGID.E. faire une description specifique." The posterior segment of the tail is in fact destroyed, but the remainder of the body sufficiently proves its complete distinction from any other known British species. It is more elongate in form than the species of ./Ega, and the two basal joints of the upper antennae are thin and subcylindric, inserted beneath the conically anteriorly produced middle of the anterior margin of the head (the nagellum is destroyed). The lower antennae are nearly one-third of the length of the body, with a stout flagellum, consisting of about thirteen articulations. They are inserted close together, and not separated by a ridge or scutcheon-shaped piece. The eyes are of large size, converging above and nearly uniting in front ; each eye consists of nine rows of facets, the middle or longest row containing thirteen lenses. The palpiform appendage of the mandibles is slender and three-jointed, the second joint thickened at the tip and furnished with ten setae set on at right angles ; the terminal joint is about two-thirds of the length of the middle one, and terminated by a strong bristle, and about seventeen short setae on its inner edge. The lateral margins of the segments of the body (especially the three posterior) are prominent and distinct, each being produced behind into a sharp point (our upper left-hand figure L to Q represents the four posterior segments of the body and the two anterior ones of the tail seen laterally). The terminal segments are traversed with a slightly ele- vated carina ; the legs are rather longer than in the species of ./Ega ; the three anterior pairs are strong, with the hand and wrist armed with a few short strong spines, and the finger unguiculated, having the base dilated so as almost to resemble a separate joint. The tail is as wide as the body ; the anterior segment is narrower than the following, and very short, the sides ending in acute spines ; ROCINELA DANMONIENSIS. 293 the three following segments arc much larger and wider, with the sides ending in acute recurved processes ; the fifth segment is as long as the preceding, but abbreviated at each side, and the sixth is obtusely triangular. We have received it from Polperro, where it was taken by Mr. Loughrin, and there are specimens in the British Museum from Ireland that have the caudal termination more pointed than in our figure. 294 ISOPODA. NORM A LI A. Genus— CIROLANA. (Leach.) Generic character. Pereiopoda formed for progression, each terminated by a slender nearly straight dactylos ; lower antennae long ; superior short, cylindrical ; pleon formed of six distinct segments; eyes small, granulated; head with submarginal channels. THE animal is elongated and cylindrical-ovate; the head is semicircular (owing to the deep emargination of the following segment), with a minute triangle interposed between the base of the upper antennae ; it is also marked with an impressed line on each side near the outer orbit of the eyes, and another finely impressed line runs closely parallel with the anterior margin. The eyes are small, but strongly granulated. The upper antemise are scarcely more than half the length of the head, the two basal joints broad and rather flat, the flagellum small, conical, and with about ten articulations ; the upper antennae are inserted beneath the latter ; the two basal joints are short ; the third, fourth, and fifth more elongated, and the flagel- lum is long and slender, composed of more than thirty articuli, extending as far as the third or fourth segment of the body ; this lower pair of antennas are separated at the base by a narrow elevated ridge, arising from a small triangular piece which rests upon the front margin of the transverse emarginate labrum. Careful figures of the mouth-organs of C. hirtipes are given by M. Milne Edwards in the Crochard edition of the "Regne Animal." The mandibles are strong, angulated beyond the CIROLANA. 295 middle, with several powerful acute teeth and an inner movable lobe ; the palpiform appendage is long, three- jointed, and bent over the base of the lower antennae. The pair of foot-jaws are moderately strong, composed of six nearly equal-sized joints, deeply ciliated along the inner edge ; the first pair of maxillae are triangular, with the extremity narrowed, bearing an inner lobe of the same length as the extremity of the organ. The second pair of maxillae are larger, stronger, and exarticu- late, with the extremity curved and acute, furnished near the base of the inner margin with a small movable quadrate lobe, the inner margin itself armed with strong bristles. The tail is not quite so broad as the body, with the four basal segments of equal size, transverse, the fifth as long as the preceding, but abbreviated on each side, with the posterior margin straight, and not arched as in the preceding segments. The last segment of the tail forms a large triangular smooth plate, on the outer anterior sides of which are affixed the lateral appen- dages, of which the inner plate is the larger : they do not extend beyond the extremity of the terminal segment. 296 ISOPODA. NORM A LI A. MGIDM. CIROLANA CRANCHII. Specific character. Animal subeylindrico-ovate, smooth, finely punctured ; segments with a slender pale line on the posterior margins, terminal segment of the pleon triangular, slightly rounded at the extremity, inner plate of the posterior appendages of the pleon larger than the outer, rather obliquely truncate, legs slightly spined. Length, three-fifths of an inch. Cirolana Cranchii. LEACH, Dictionn. Sci. Nat. xii. p. 347. DESMAREST, Cons. Crust, p. 303. MILNE EDWARDS, Crust, iii. p. 236. WHITE, B. M. Cat. Brit. Crust, p. 79. Pop. Hist. Brit. Crust, p. 249, pi. xiv. f. 3. GTOSSE, Man. Mar. Zool. i. fig. 230. THE preservation of Dr. Leach's typical specimen of this species, having the name Cranchii still attached to it in his small and very neat hand-writing, enables us to clear up the short and unsatisfactory descriptions of it given by M. Milne Edwards and A. White. The former CIROLANA CRANC1III. 297 confines his specific description to four lines, given as a quotation from Leach : " Corps lisse ponctue ; le dernier article de 1'abdomen triangulaire, arrondi a son extre- mite, lame externe des dernier es fausses pates plus grande et plus large que T interne ; cette derniere tronquee a son extre,- mite"* Leach's description is, however, confined to the pereion and last joint of the pleon, and M. Milne Edwards appears to have intercalated the latter portion of his characters from Leach's general observations on the third race of the Cymothoadae (comprising the genera Eury- dice, Nelocira, and Cirolana) : " dans ces trois genres la petite lame ventrale posterieure externe est plus grande et plus large que 1'interieure." In Eurydice, however, as well as in the only species of Cirolana described by Leach, the inner plate is considerably the larger, its inner margin being somewhat obliquely truncate, whilst the outer plate is the smaller, and is more or less pointed. Mr. A. White unintelligibly says, " small plates of the posterior ventral appendages larger and wider than the inner." As will be seen in our lower left-hand figure vat the head of this species, the outer plate (at the right side of the figure) is small and elongate-conic, the inner plate much larger, and somewhat obliquely truncate, whilst the basal portion is furnished with a conical point, extending half the length of the inner plate. The appendages as well as the edges of the terminal segment of the tail are strongly fringed with setae. The legs are but slightly spinose and rather slender. The ridge between the base of the lower antennae is not so narrow as in C. spinipes. * M. Milne Edwards, in his generic character of Cirolana, describes the two plates of these lateral caudal appendages as being "a peu pres de meme grandeur," but in his description of C. hirtipes he says that " 1'interne est plus large que 1' externe," and in C. elonyata " lame externe toe's petite, 1'in- terne grande et arrondie au bout." 298 The original specimens of this species were forwarded to Dr. Leach from Falmouth (Cornwall), by Mr. J. Cranch. They have afforded the materials for our figure and description, and we have dredged a specimen, near the Knapbuoy, outside the Plymouth Breakwater, in about six fathoms of water. We have also received it from Mr. D. Robertson, of Glasgow, taken at Cumbrae. The accompanying vignette of Dutch fishing boats is from a painting in the possession of J. Thackeray, Esq., of Amo Vale, Nottinghamshire. DUTCH FISHING BOATS. CIROLANA SPINIPES. 299 1SOPODA. NORM All A. CIROLANA SPINIPES. Specific character. Ceplmlon wider than long, with a curved incised line on each side parallel with the lateral margin. Pereion very convex, smooth. Pereiopoda strong and broad, armed with numerous spines ; inner ramus of the posterior pair of pleopoda (uropoda) larger than the outer, elongate- ovate, acute at the tip, basal joint produced into a short subconical point. Length, nearly one inch. Cirolana hirtipes ? MILNE EDWARDS, Crust, iii. p. 236, t. 31, f. 25. CUVIER, Regne Animal (Edit. Crochard), Crust, t. 67, f. 6 ? W. THOMPSON, in Ann. Nat. Hist, xx. p. 246. WHITE, B. M. Cat. Brit. Crust, p. 79. Pop. Hist. Brit. Crust, p. 850. THIS species is at once distinguished from the typical C. Cranchii — the only one hitherto described as a native of Northern climates — by its robust form, convex glossy body, thick spinose legs, and by the shortness of the 300 produced inner angle of the basal joint of the lateral caudal appendages. This last character, as well as the diversity of habitat, induce us to consider our second native species as dis- tinct from the C. spinipes of Milne Edwards, who gives the Cape of Good Hope as its locality, with which it was considered as identical by Mr. A. White. The general form is elongate-ovate, somewhat com- pressed at the sides, giving the body a convex appear- ance ; it is very glossy and impunctate ; the pleon is not quite so broad as the seventh segment of the pereion. The head is large, wider than long (in which respect also the animal differs from C. spinipes as described by Milne Edwards), somewhat rounded in front, marked at each side with the impressed line which appears to be a character of the genus. The upper antennae are very short, composed of two small square flattened joints, with a short conical ten-jointed flagellum. The lower antennas are nearly half the length of the body, com- posed of two very short and three long basal joints, and a long and slender flagellum, consisting of about twenty- four articuli. These antennae are separated from each other at the base (when seen from beneath) by a narrow elevated ridge, below which is a broad, short upper lip, with the sides rounded, and the middle of the free margin slightly emarginate ; the mandibles are very robust, fur- nished with a triarticulate palpi form appendage (one of which is seen in our lower left-hand figure at d"}. The legs are strong, with, especially, the middle joints broad, and subtriangular, their upper angle being produced into a point ; on the outside they are armed with numer- ous strong bristles or slender spines, a character which appears to us not to accord with Milne Edwards's de- scription, " pates tres-poilues," of his C. hirtipes. The CIROLANA SPINIPES. 301 terminal segment of the pleon is as long as the preceding three segments united ; it is somewhat triangular, with the lateral margins rounded and the extremity rather pointed ; the lateral appendages of this segment are thin, the inner plate larger than the outer, elongate- ovate, scarcely pointed at the tip ; and the basal joint is prolonged into a short triangular point, corresponding with the " grande dent lamelleuse et aceree qui atteint le milieu des lames terminales" of C. hirtipes as described by Milne Edwards. A specimen of this species was first noticed by the late Mr. W. Thompson, which was procured in a fishing boat in Dublin Bay, by Mr. T. W. Warren, in 1847. This specimen has furnished the figures at the head of this description. Another specimen is in the British Museum, from Belfast Bay, taken out of a holibut, and several specimens are in the Hopeian collection, at Oxford, one of which is labelled " Brighton," and another was, we believe, taken off the Yorkshire coast. We have also received it from the Moray Frith, where it was taken by Mr. Gregor. M. Hesse, Ann. des Sc. Nat. vol. v. p. 257, 1867, describes several species of this genus that he has taken burrowing in the sand on the coast of Britanny. -. • *».- - • ' *' •N * 302 ISOPODA. NORMALIA. Genus— CONILERA. (Leach.} Generic character. Subcylindrical, pleon as wide as the ter- minal segments of the pereion, four anterior pairs of legs strong, three hind pairs slender; maxillipeds with the three terminal joints broad and flat, outer pleopoda divided into two nearly equal-sized joints. THE very short characters given by Leach of this genus, and by Montagu of the only known species, having been insufficient to afford any true idea of the relations of the type, we are happy in being able to furnish detailed figures of the chief external organs. The animal is nearly cylindrical in form, with the sides of the body nearly parallel, the head semi-oval, deeply immersed in the first large segment of the body, of which the anterior lateral angles are considerably ad- vanced ; the tail is composed of four nearly equal-sized, short basal segments (the first more or less concealed beneath the preceding), followed by the fifth, which is contracted at the sides, whilst the sixth is elongate- triangular. The upper antennae are short, with the basal joints subcylindrical ; the second pair are about twice the length of the preceding, separated at the base by a narrow ridge ; the labrum is transverse, rounded at the anterior angles. The mandibles are tridentate at the tips, with a slender serrated inner movable lobe, and a three-jointed palpiform appendage. The maxillipedes or foot-jaws are CONILERA. 303 six-jointed, flat, with the three terminal joints very broad, and gradually decreasing in size. The first pair of maxillae are terminated by two somewhat triangular ciliated lobes ; the second pair of maxillae are trilobed, the outer lobe subtriangular and armed with a row of strong bristles ; the innermost lobe is compound, and terminated by three small appendages (fig. f"). The four anterior pairs of legs are robust, with the middle joints produced above into a strong angle. The three hind pairs are much more slender, and terminated by a very minute hook. The anterior pair of pleopoda are formed of two nearly equal joints, whilst the large lateral appen- dages of the last segment of the tail have the outer edges of the two divisions strongly notched. JSGID.E. ISOPODA. NORMAL! A. h CONILERA CYLINDRACEA. Specific character. Upper antennae reaching to the eyes, lower antennae reaching to half the length of the first segment of the body, inner division of the uropoda much larger than the outer, ovate, with the extremity pointed and the outer lateral margin notched, basal joint not having its inner angle produced into a point. Length, about three-quarters of an inch. Oniscus cylindraceus. MONT., Trans. Linn. Soc. vii. p. 71, t. 6, f. 8. Conilera cylindracea. WHITE, B. M. Cat. Brit. Crust, p. 80. Pop. Hist. Brit. Crust, p. 252, pi. xiv. f. 6. G-OSSE, Man. Mar. Zool. fig. 234. Conilera Montagui. LEACH, Trans;-- Linn. Soe. xi. p, -370. Dictionn. Sci. Nat. xii. p. 349. DESMAREST, Cons. Crust, p. 305. MILNE EDWARDS, Crust, iii. p. 242. WHITE, B. M. Cat. Brit. Crust, p. 80. Anthura cyUndrica. LEACH, Trans. Linn. Soc. xi. p. 366. WHITE, B. M. Cat. Brit. Crust, p. 67. CONILERA CYLTNDRACEA. 305 THE whole upper surface of tins animal is smooth, glossy and impunctate, of a pale yellow colour, clouded with cinereous on the sides. The eyes are small and distant apart ; the antennae short, the upper not extending beyond the eyes, composed of four rather strong sub- cylindrical basal joints, and a flagellum of about seven articuli ; the lower antennas (separated from each other by a narrow raised ridge) are rather more than twice the length of the upper pair ; they consist of four short basal joints, a fifth slender joint, and a flagellum with about twelve articuli. The labrum is trans- verse, with the anterior angles rounded, and the middle of the free margin slightly emarginate. The man- dibles are robust and horny, with the apex incurved and three-toothed, the middle of the inner margin fur- nished with a slender movable appendage slightly ser- rated on its upper edge ; the foot-jaws are broad, shutting the mouth from below, six-jointed, the three terminal joints broad and flat, with their outer margins setose. The first pair of maxillae are composed of a broad basal joint terminated by two somewhat conical lobes, of which the outer is divided into two parts by an oblique articu- lation. The second pair of maxillae (represented more magnified than the preceding mouth-organs) are termi- nated by three lobes, of which the outermost is largest, somewhat triangular, and furnished with strong bristles on its inner edge ; the middle lobe is a slender simple piece, but the innermost lobe is much more complicated, terminated by three small pieces, of which the outer is slender, curved, and setose at the tip ; the two inner lobes are of equal size, conical, and strongly and transversely verticillated across their centre. The three fore pairs of legs are short and very robust, with the middle joints broad, flattened, and produced into an angle on VOL. II. X 306 JEGJD.E. the outside and serrated on the inside. The fourth pair of legs are intermediate in size, between the three fore and three hind pairs, which latter are slender ; all the legs are terminated by a small hook-like finger, which appears to be articulated at its tip in the hind legs. The terminal segment of the tail is obconical, with the sides slightly curved and the extremity rather rounded. The anterior pair of pleopoda are strong, and form an operculum, of which the basal joint is large and oblong, and the twro terminal divisions unequal, the inner one being the larger, with its inner edge straight, whilst the outer one is more ovate ; the lateral appen- dages are also unequal, the inner lobe being the larger and ovate, with its apex acute, the outer margin beyond the middle somewhat notched and spinose. It will be seen by a comparison of our description and figures of the parts of the mouth with those of the genus Cirolana, given in the Crochard edition of the tf Regne Animal," that this animal is closely allied to the last- named genus, and that it has no other relation with Anthura than its narrow cylindrical form. The species was first obtained by Colonel Montagu on the coast of Devonshire ; we have procured it by dredging in the Sound, and in six fathoms near the Knap Buoy, and from trawlers off Plymouth, and have received it from Mr. Loughrin from Polperro, and from the Frith of Clyde, taken by the Rev. A. M. Norman. Dr. Lukis, of Guernsey, took upwards of a dozen specimens feeding together within the orbit of the eye of a whiting, the eye- ball of the fish being nearly detached from the surround- ing parts. The fish did not seem to be out of condition, although the parasites must have been there some time, as they were remarkably blanched. EURYDICE. 307 I SO POD A. NORM All A. Genus— EURYDICE. (Leach.) S L A B B E R I N A. (Van Beneden.) Elongate-ovate, moderately convex ; upper antennae very short, cylindrical ; lower antennae long, with a multiarticulate slender flagellum ; legs small ; uropoda with the inner division larger than the outer, and hatchet-shaped. THE only two characters given by Dr. Leach of this genus, namely, the " abdomen compose de 5 articles," and " yeux lisses," which are described as separating it from Nelocira (in which the pleon is described as having five segments, and the eyes being granular), and also from Cirolana (in which the pleon has six segments, the eyes being also granular), are unsatisfactory, and have induced M. Milne Edwards to unite Nelocira with Eurydice, especially as the figure given by Desmarest of the former of these two genera represents it with a six- jointed tail ; whilst Van Beneden expressly says that the eyes are distinctly faceted in the animal, which he has described and figured under the name of Slabberina agata, and which is certainly identical with the Eurydice pul- chra of Leach. Van Beneden, moreover, represents the tail as formed of a large exarticulate mass, in which the five anterior segments are only indicated by partial longitudinal mark- ings on the skin, followed by a sixth narrow segment and a seventh large terminal semi-ovate one. He also describes and figures the upper antennas as x 2 308 composed of only three joints. A very careful exami- nation of the species has, however, shown that in all these characters Van Beneden has fallen into some unaccount- able error. The eyes under a strong lens are not faceted. The seventh or last segment of the body is considerably shorter than the sixth ; the first segment of the tail is still shorter and abbreviated at the sides, whereas the second, third, fourth, and fifth segments are of equal size, perfectly distinct in their articulations, and with the posterior-lateral angles of each produced into an acute point like the terminal segments of the body ; the sixth or terminal segment of the tail is of large size, semi- ovate, and has a deep transverse impression near the base (this impression is not represented in our outline figure, but it seems to correspond with Van Beneden's narrow penultimate segment). The upper antennas are very short and cylindrical, composed of three basal joints, arising from a fixed base, the third being as long as the two preceding joints taken together, followed by three small articuli, of which the last is very minute, and almost concealed by terminal setse. The lower antennas are about two-thirds of the length of the animal, having five basal joints, thicker than the remainder, extending to the extremity of the upper antennas, followed by a long very slender flagel- lum, composed of a great number of minute articuli. The mandibles are horny, with several conical teeth at the tip, and with a slender movable blade attached to the inner margin, having a finely serrated upper edge. They externally bear a slender three-jointed palpiform appendage. The foot-ja\vs are six-jointed, the joints of moderate width, the second having the inner apical angles pro- duced, the remainder being armed with bristles on the EURYDICE. 309 inner edge ; the outer maxillae (e) are apparently formed of three closely soldered joints, indicated by bristles, on the inner edge, the second and third joints being pro- duced on the inner margin. The inner maxillae are bilobed, the outer division broader than that of the outer pair, and armed with"~stronger bristles, the inner division minute and armed with bristles set on at right angles. The four anterior pairs of legs are rather shorter than the three posterior ones, the former being armed with short spines on the lower edge, whilst the hind ones are smooth, having the outer angles of the middle joints conically produced and setose. The uropoda, or lateral appendages of the tail, arise on each side from a broad basal joint, the inner division being larger than the outer and obliquely truncate at its extremity ; both having ciliated margins. 310 fSOPODA. NORMALIA. EURYDICE PULCHRA. Specific character. Eyes not faceted, body semi-transparent, pale ashy colour, figured symmetrically with dark markings, resembling the star- like spots in agate, basal segments of the pleon with a large transverse mark on each side formed of small black lines. Length, one-quarter of an inch. Ayaat Pisselet. (ONiscus) SLABBER, Naturk. Verlust. p. 149, pi. 17, f. 1, 2. Eurydice pulchra. LEACH, Trans. Linn. Soc. xi. p. 370. Dictionn. Sci. Nat. xii. p. 347. Suppl. Enc. Brit. i. p. 428. SAMOUELLE, Eutom. Compend. p. 109. DESMA- REST, Cons. Crust, p. 302. MILNE EDWARDS, Crust, iii. p. 238. W. THOMPSON, in Ann. Nat. Hist. xx. p. 240. WHITE, B. M. Cat. Crust, p. 79. Pop. Hist. Brit. Crust, p. 250. GOSSE, Man. Mar. Zool. i, fig. 231. HESSE, Observations biologiques sur quelques Crust, des Cotes de Bre- tagne, Ann. des Sc. Nat. v. p. 242 (1866.) Sldbberina agata. VAN BENEDEN, Recherches sur la Faune litt. Belg. p. 88, pi. 15 (1861). EU11YDICE PTJLCHRA. 311 THIS beautiful little species was first described and figured by Slabber, in bis fine microscopical work, above referred to. His article on it lias, however, been overlooked by all carcinologists, except Van Beneden, who has published a detailed account of it in his re- searches on the littoral fauna of Belgium, and who remarks that no naturalist had reobserved Slabber's animal; this is not indeed surprising, since the de- scription of it by Leach (which has hitherto served for all subsequent writers on this tribe) is so short and unsatisfactory as not to be readily recognized. The body is smooth and of a pale grey colour, each segment marked with about eight or ten black dots formed of delicate radiating lines, closely resembling the markings upon certain varieties of agate ; these spots are arranged transversely and with a great amount of regularity upon the succeeding segments ; each of the basal joints of the tail, on the other hand, is marked with two transverse spots formed of a series of very fine black lines ; the large terminal segment is transversely depressed near the base ; the tail is furnished on its underside with five pairs of foliaceous membranous plates, each articulated across the middle, the basal division being almost square, and the apical division nearly semi- circular, the latter fringed all round with about twenty- five very fine hairs, each of which is fringed along its whole length with most delicate cilia ; the outer pair of the caudal plates do not perform the duty of an opercu- lum as in the Idotese, and the sides of the terminal segment are furnished with lateral appendages, the outer division of each of which is smaller than the inner por- tion, which is obliquely truncate at its extremity, and hatchet-shaped. This species is found in small pools left by the re- 312 vEGID.E. tiring tide, where it swims about with the utmost celerity. It is not difficult to keep it alive in confinement, Slabber having kept one for nine days in the month of August. It occurs on the coast of Devonshire, where it was taken at Bantham by Dr. Leach, and in South Wales by our- selves, on Loughor Marsh, and on a cuttlefish shell on the beach in Caswell Bay, and Mr. W. Thompson obtained it from Larne. Van Beneden states that he only found it in summer ; it was, however, taken at Carrickfergus, by Mr. Hyndman, on the 17th of March, 1840. M. Hesse has found it burrowing in sand on the coast of Britanny. The Rev. A. M. Norman has sent it to us from the coast of Northumberland and Durham, and Mr. Walker of Brookfield, near Cheshire, writes us that " Corophium longicorne and Eurydice pulchra are the com- monest Crustacea in the Dee, at least at Bagillt, where his observations have been made. " The latter," he says, " is a most savage little beast. If you are a moment still in the water while bathing, dozens will fasten upon you and nip most unpleasantly. I have had to jump into the water again after coming out from bathing and splash violently to get rid of the hosts that had stuck to me while clinging to the side of the boat preparatory to getting in. They continue to bite after you are out of the water. I once put a wretched Hyperia which I had taken from a Rhyzostoma, into a small bottle with two Eury dices ; the bloodthirsty little brutes attacked him at once like tigers, and soon sucked his shell clean." ASELLIDJE. 313 Tribe— LIBERATICA. THE remainder of the aquatic Isopoda are free in their habits, not residing as parasites on the bodies of fishes or other sea animals. Their legs are consequently not formed for prehension or attachment to their prey, nor armed with a strong hook at the extremity, but, on the contrary, they are slender, and generally of uniform size and structure, and fitted for locomotion. They con- stitute five families — Asellidcs, Munnopsidce, Arciuridce, Idoteidce, and Sph&romidae. Family— ASELLIM;. THE animals composing this family are of a sub- depressed form ; and have not the posterior pair of pleopoda developed into an opereulum to the remainder of the respiratory apparatus (in which respect they differ from the Idoteida and Arcturida, whilst the Sphceromida have the body very convex, and capable of being rolled up into a more or less perfect ball). The mandibles are armed with a palpiform three-jointed appendage ; the first two or basal joints of the foot-jaws are strongly produced on the inner margin, and the outer maxillae terminated by three large flattened membranous plates. The genus Limnoria differs in several important re- spects from the other genera of this family, and was in fact considered by Dr. Leach to form a separate class amongst his Cymothoades. 314 ASELLDXE. ISOPODA. ASELLIDJE. NORM ALIA. Genus. J7ERA. (Leach.} Generic character. Upper antennae very short. Lower antennae more than half the length of the animal. Legs uni- form, slender. Pleon coalesced into one segment, furnished with two minute subterminal uropoda. Pleopoda or branchial appen- dages covered by a large plate occupying the entire under surface of the pleou. Dactyla biunguiculate. THE small flattened species, which is the type of the present genus, is distinguished from the allied genera by the minute upper antennae and terminal appendages to the tail, the claws with which the moderately long slender uniform feet are furnished at the tip, and especially the very remarkable structure of the under surface of the tail. The body is considerably flattened, and elongate- ovate (or narrow in some exotic species). The head is not soldered to the following segment of the body ; its sides are rounded, having, like the segments of the body and the tail, a thin lateral margin. Its fore margin is bi-emarginate, the antennae not having their basal joints concealed, but arising within the emargination. The upper or inner antennae are very small and four-jointed, not extending to the third joint of the outer pair, which are considerably more than half the length of the entire animal, with the two basal joints short, the third twice the length of the preceding, the fourth long and more slender, but thickened towards the tip, followed by a very long and slender multiarticulate flagellum. The J/ERA. 315 mandibles are strong, horny, curved inwards at the tip, and armed with several teeth, the lowest of which is truncate. They are provided with a three-jointed palpi- form appendage. The basal joint of the foot-jaws is large and triangular, with the tip ciliated, followed by five joints, of which the distal ones are the most slender. The first pair of maxillae are furnished at the extremity with three oval membranous plates, ciliated at their extremities, the anterior one being the largest. The second maxillae are composed of two branches, of which the outer one is the larger, and armed at the tip with strong bearded bristles. The segments of the body are strongly marked by lateral incisions, the sides being rounded, and the pos- terior-lateral margins not produced into a point. The legs are of moderate size, being nearly uniform both in length and thickness, and terminated by two small hooks of nearly equal size. The female carries between the base of the legs an ovigerous pouch, composed of delicate membranous plates, within which the young are deve- loped. The tail consists of only a single plate, formed by the coalescence of all the segments of the pleon, which is semicircular (or semi-ovate) in form, and, in our British species, with a small semicircular incision in the middle of the posterior margin, within which are attached the two very minute terminal appendages, each of which consists of a square flat joint, supporting two extremely minute conical plates, of which the outer one is almost obsolete ; the tips of these plates are furnished with hairs. In J. Kroyerii the tail has two small semicircular incisions, between which the centre is produced into a small point, and the appendage on each side consists of a small square basal joint, supporting two minute oval plates. 316 ASELLID^E. We have been under the necessity of sinking the genus Jceridina of Milne Edwards since our discovery that the " absence de la grande lame operculaire," which in Java " remplace les premieres fausses pates," is a sexual character. The type J. Nordmanni of Rathke must, moreover, be removed from Janira, to which genus it was referred by the last-named author, as it wants the long styliforni processes at the end of the tail. The following vignette of Brighton Fishermen was kindly done for this work by Mr. Jennings. BRIGHTON FISHERMEN. JyERA ALBIFRONS. I 'SO POD A. NORMAL! A. 317 ASELLID^. J&RA ALBIFRONS. Specific character. Subovate, very depressed, sides of the ceplialon, pereion, and pleon margined. Colour cinereous, with the anterior margin of cephalon whitish. Length, about one-sixth of an inch. Oniscus albifrons. Jcera albifrons. Jcera niraUs 1 Oniscus marinusl MONTAGU, MSS. in Brit. Mus. LEACH, Edinb. Encycl. vii. p. 434. Trans. Linn. Soc. xi. p. 373. Suppl. Enc. Brit. i. 428. SAMOUELLE, Ent. Compend. p. 110. DESMAREST, Cons. p. 316. MILNE EDWARDS, Crust, iii. p. 150. W. THOMPSON, in Ann. Nat. Hist. xx. p. 245. WHITE, B. M. Cat. Brit. Crust, p. 69. Pop. Hist. Brit. Crust, p. 231. GOSSE, Man. Mar. Zool. i. fig. 243. KROYER, Gronlands Amfipod. p. 75, pi. 4, fig. 21a — k. MILNE EDWARDS, 0. C. p. 149. 0. FABRICIUS, Fn. Groenl. p. 252, n. 229. 318 ASELLID.E. THE accompanying figure of this species has been made from Colonel Montagu's typical specimens, described by Dr. Leach, in the British Museum. Not only do they X «,' •/ differ from the J. Kroyer'n of Milne Edwards, from the shores of La Vendee, in their much broader form, but they agree in this respect with Kroyer's figure of J. nivalis, from Greenland, whilst the description of the tail given by Otho Fabricius of his Otiiscus marinus ("cauda subciliata et extremitate incisuram vix notabilem habens, de qua styli duo brevissimi, acuti, distantes '*) seems also to accord with other British species. Dr. Leach, indeed, describes the eyes in his species as being " placed close together," but this character neither agrees with the type nor with the descriptions and figures of Kroyer and M. Edwards. The upper surface of the body is flattened and marked with irregularly impressed lines. The lower or outer pair of antennae are considerably more than half the lensfth of the animal. The tail is much wider than O long, being nearly semicircular in form, having two small impressed dots a little apart towards its basal por- tion ; the centre of the caudal margin has a nearly semi- circular notch, with the centre of the incision slightly produced into an obtuse point, on each side of which are implanted the minute uropoda. The general colour is ashy, but very much varied in its shades in dried specimens, with the front of the head whitish. Jeer a Hopeana of Costa (Faun. d. Regn. di Napoli fasc. 83, tav. iii.) appears to us identical with the present species, agreeing with it (contrary to Signer Costa's statement) in the position of the eyes ; the only apparent difference consisting in the equal size and apparently three-articulated structure of the two appendages of the minute terminal uropodas. JJERA ALBTFRONS. 319 J. alhifrons probably occurs all round our coasts. We have it recorded on the Devonshire and other coasts, among sea-weeds and under stones, in many parts of the British islands. It was found especially abundant in crevices of rocks at half-tide near Falmouth, by Mr. W. P. Cocks, and we have taken it abundantly beneath and generally attached to the under surface of stones between tide-marks in Plymouth Harbour, the flat surface of the body enabling the animal to ensconce itself in very slight crevices. The late Dr. Johnston also forwarded it to us from the Berwickshire coast. 320 ISOPODA. NORM All A. ASELLID^. ASELLID^E. J^ERA NORDMANNI. Specific character. Broadly ovate ; sides of the segments strongly ciliated, with hairs set on at right angles ; upper antennae four-jointed, terminal joint not multiarticulate ; lower antennre not more than one-third of the length of the animal, with the third joint not half the length of the following ; pleon with a deep semicircular notch, within which the two small caudal appendages are visible, extending very slightly beyond the margin. Length, about one-sixth of an inch. Janira Nordmanni. RATHKE, in Mem. des Sav. E^rang. de St. Petersb. (Fauna der Krym.), t. iii. pi. 6, figs. 1 — 5, p. 388. Jceridina Nordmanni. MILNE EDWARDS, H. N. Crust, iii. 150. THIS small animal was arranged by its first describer, Ratbke, as a species of Janira; but that genus possesses elongate appendages at the extremity of the body, as in the common Asellus. Professor Milne Edwards accord- J/ERA NORDMANNT. 321 ingly removed it therefrom, and formed for its reception a new genus, Jaridina, in consequence of the branchial apparatus on the underside of the tail not being covered by a " grande lame operculaire qui chez eux remplace les premieres fausses pates ' (which had been given as the generic distinction between Asellus and Jcera). Having, however, ascertained that this "grande lame" is a sexual distinction peculiar to the females, we are under the necessity of referring the new species to the genus Jara, with which it agrees in all its essential characters. It is considerably broader than /. albifrous, the lateral margins being very thin and dilated, as well as ciliated with rather strong bristles set on at right angles, a peculiarity of structure eminently fitted for enabling the animal to reside in flat crevices, beneath stones, &c., in situations often uncovered by the tide ; the ciliation of the sides of the body serving for the retention of the fluid which supplies the material for respiration ; just as in many insects residing in occasionally submerged situations under stones, it maintains a supply of air for the like purpose. The head is deeply incised in front, for the reception of the antenna?, the inner pair of which are very short, and four-jointed, the terminal joint offering no apparent trace of articulation ; the outer antennae are not more than one-third of the length of the animal, the third joint being only about twice the length of the preceding, and not half as long as the following joints, the flagellum is very slender and multi- articulate. The terminal segment, or tail, is large and semicircular, with a rather deep semicircular incision at its extremity, within which are affixed the two caudal appendages, consisting of a small oblong basal joint, at the extremity of which are attached two small scales, the outer one being extremely minute and conical, the Y 322 ASELLID.E. inner one large and oval, setose at the tip. The outer ventral scales are free, forming together nearly a circle, each divided into two nearly equal parts by a somewhat diagonally-placed articulation ; at their base is attached, in the males, two minute triangular plates and the elongated male organ, which extends to the above-men- tioned articulation. The legs are terminated by two minute curved ungues. Rathke obtained his specimens at Cape Parthenon, in the Crimea, under stones ; our specimens were taken at Plymouth, and in Langland Bay, South Wales. MUNNA. 323 1SOPODA. NORMALIA. Genus — MUNNA. (Kroyer.) Male. Elongate, sublinear. Female. Broad, ovate. First and seventh segments of the pereion shorter than the rest ; cephalon very broad and large, occupying nearly one-fifth of the whole length of the animal. Eyes very large, fixed at the postero-lateral angles of the cephalon, pedunculated, immovable. Upper antennae very short ; lower antennae very long. First pair of legs small and strong ; the remainder very long and slender, terminated by two small ungues. Pleon having all the segments coalesced into a single elongate pear-shaped plate. THE large size of the head, together with the very pro- minent, pedunculated (although not movable) eyes, which stand out, in the males, considerably beyond the lateral margin of the body, gives a very distinctive character to this genus ; and the great length of the lower antennae and legs, giving the animals the appearance of one of the Nymphonidce, at once separates it from all the other genera in the present family. The facets of the eyes are large and hexagonal; the antennae are inserted at a considerable distance apart (represented in our lower left-hand outline in the woodcut of M. Kroyeri), the upper pair consists of several very short joints, followed by a long, slender portion, which is exarticulate in M. Whiteana, but distinctly consists of three joints in M. Kroyeri ; this portion is terminated by two flattened (and articulated ?) setae at the tip, at the base of which are affixed two or three very minute joints, observed only by us in M. Whiteana, and which constitute the true flagellum. The lower antennae are very long, Y 2 324 ASELLIDJE. exceeding the whole animal in their length, with a four or five-jointed peduncle (of which the two last joints are long and subequal), and a multiarticulate flagellum half the length of the entire antennae. The segments of the body are suhequal in length, but the first and seventh are often shorter than the rest : in the males, the body is narrow, with the sides parallel ; but in the female, the outline of the animal is ovate, or pear- shaped. The foot-jaws consist of a large basal joint, armed at the base with an elongated triangular scale, and produced on its inside into a flattened blade, rounded at its extremity and ciliated, and followed by four distinct joints, gradually becoming more slender, and furnished with strong bristles at their distal extremities. The mandibles are robust, and armed on the inner edge with a strong molar tooth, and at the base, on the outside, with a three-jointed palpiform appendage. The fore legs are short but strong, and furnished with a subcheliform hand, whilst the six remaining pairs of legs are very long, and terminated by two long, slender, simple ungues. The tail consists of a single piece, of a flattened ovate form, narrower than the segments of the body. We presume that in this genus the sexes are distinguished by the same condition of the branchial plates as we have above stated to occur in several of the other genera of this family. Kroyer, in his characters of the genus, says " unica infra lamina praeditum tectoria," whilst H. Goodsir represents the " abdominal plate," as he terms it, as composed of two long and narrow pieces soldered together along their inner margins, copied in our cut of M. Kroyeri ; but on referring to Kroyer's original description, we perceive that it is taken from the female of M. Boeckii, whilst H. Goodsir's description is taken from a male animal. MUNNA. 325 The eggs in this genus are carried in a large ovisac, situated between the middle legs, and composed of four large plates. As it is very probable that Kroyer's two species will be discovered in our northern seas, we add his characters of both. Munna Fabricii, Kr., abdomen ovale vel subellipticum, aperte longius quam latum ; appendicibus caudalibus rudi- mentariis sed sat distinctis. Annulus thoracicus sep- timus sat distinctus. Munna Boeckii, Kr., abdomen capite aperte longius subconicum non multo latius quam longum, appendi- cibus caudalibus fere evanescentibus ; annulus thoracicus Septimus parutn distinctus, sexto multo brevior. The following vignette represents the rudimentary uropoda of — 1. Munna Kroyeri. 2. Munna Whiteana. 3. Leptaspidia brevipes. 326 ISOPODA. NORM A LI A. ASELLlDrf. a MUNNA KROYERI. Specific character. Male with the eyes very prominent, extending con- siderably beyond the pereion. Pereion setose. Pleon scarcely longer than wide. Carpus of first pair of gnathopods thick, with strong spines on the under edge, and two strong spurs at the tip beneath. Upper antennae ter- minated by two long articulated setas, and a very minute flagellum. Length, one line. Munna Kroyeri. GOODSIR, Edinb. New Phil. Journ. xxxiii. p. 365, t. 6, f. 6 (1842). W. THOMPSON in Ann. Nat. Hist. xx. p. 247. WHITE, B. M. Cat. Brit. Crust, p. 70. Pop. Hist. Brit. Crust, p. 231, pi. xiii. f. 3. THE male of this species has only hitherto been ob- served. It has the " whole body very setose, and is of an ochrey-brown colour, except the reticulated portion of the eyes, which are black. The head is large, rounded anteriorly, and slightly pointed in the middle. The ter- MUNNA KROYERI. 327 niinal joints of the foot-jaws are seen projecting in front of the anterior edge, and they are always in motion. The dorsal surface of the head is quite smooth, and the internal or superior antennae arise from it within the margin, and a little anterior to the eyes ; they are composed of a peduncle of three articulations, and of a double multi- articulate setaceous portion, which arises from the last joint of the peduncle : these are very slender, and incline towards one another at their extremities ; the whole organ is equal in length to the two first joints of the inferior antennae and the proximal half of the third joint. The external antennae are much produced, being considerably longer than the body; the peduncular portion is composed of four joints ; the setaceous flagel- lum is multiarticulate ; two large blood-vessels are seen running through these organs. The eyes are large and pedunculated, but quite immovable ; the reticulated portion is small, and is almost altogether confined to the lower surface. " The first six segments of the body are almost equal, the seventh is obsolete. The first pair of legs are pre- hensile, and the mechanism is rather curious ; the fifth joint is very large and rounded, the inferior angle of its distal extremity is armed with four large and strong teeth, two of which are large, the other two being smaller ; the sixth joint is not so large, and is reniform ; the seventh joint is long and pointed, bearing at its ex- tremity a strong claw. The following six pairs of feet are ambulatory. They are very spiny, and the last joint is armed with two strong claws, which are not placed in the usual way, but with the one above the other ; the superior is largest and strongest. The tail is composed of two segments : the first, which is largest, is of a square shape, and is armed with two strong spines at its pos- 328 ASELLID^E. terior angles. The last segment is almost triangular ; the apex being directed posteriorly, two small styles arise from each side of the apex." [We have copied Mr. Goodsir's figure of the tail at z, which shows that there is only one pair of caudal styles, and not two pairs, as his description would lead us to infer.] " All the external margins of both of these segments are thickly fringed with minute hairs and spines. The branchiae are almost semicircular, and each of them is armed on its internal edge with a small appendage. The external plate of the branchiae is extremely narrow, and is not composed of two equi- lateral pieces, as in the other Asellida, but consists of one piece only, with an immovable suture in its mesial line. It is attached to the body by its base only." This species was found by the late Mr. H. Goodsir in the Frith of Forth. It is quick and active in its move- ments, running among the branches of coralline with great rapidity. Mr. Goodsir never observed it swim- ming, its legs being, indeed, unfitted for that kind of locomotion ; when pursued along the bottom, it runs quickly, but often stops suddenly, turns round, and assails its annoyer. We have received it from Mr. Robertson, who took it at Kames Bay, and from the Rev. A. M. Norman, who found it at Cullercoats and Seaham. MUNNA WHITEANA. ISOPODA . NORM A LI A. 329 ASELLID^E. MUNNA WHITEANA, Specific character. Male, with the cephalon nearly half the length of the pereion, with the eyes very wide apart, fixed on thick peduncles. Upper antennse with four very short basal joints, followed by a very long slender- one, terminated in a short triarticulate flagellum, and two long auditory cilia. Pleon about as long as the cephalon, narrower than long, armed with three strong teeth at each side. Length, rather more than half a line. THE head is very large and broad, increasing in width posteriorly, equal in length to the three following seg- ments ; the eyes are fixed on very thick and prominent peduncles. The front of the head is nearly truncated, and the upper antennae are affixed widely apart next the anterior-lateral angles of the head. The peduncle consists of four very small joints, of which the first is most robust, and a fifth, that is very long and slender, 330 ASELLIDJL which is terminated by a flagellum composed apparently of three very minute articulations, at the base of which arise two delicate, slender filaments or auditory cilia, about half the length of the preceding joint. The lower antennae are much longer than the entire animal, and consist of three small basal joints, followed by two long and slender ones, occupying nearly half the length of the whole antennae, followed by a long and slender multiarticulate flagellum. The first segment of the body is nearly as large as each of the three following, whilst the three terminal segments gradually decrease in width and length, each having the sides produced into rounded lobes. The tail is elongate-ovate in form, con- stricted at the base, with three strong teeth on each side, the last part being affixed in a slight incision on each side near the tip, and apparently representing the minute caudal appendages. The fore legs are short and subchelate, the three follow- ing long and slender, whilst the three posterior pairs are still longer, all except the anterior pair being terminated by two strong curved ungues of unequal size. This species was first named by us Monimia Whitiana, in compliment to Mr. Adam White, late of the British Museum, and described at the meeting of the British Association for 1S52, from a specimen obtained at Wey- mouth by Professor Williamson ; and we have since received it from Cumbrae, where it was taken by Mr. David Robertson, of Glasgow, amongst the fibres of the nest of Lima hians. They were generally much covered with particles of fibre, and were sluggish in their movements. LEPTASPIDJA. 331 IS OP ODA . A SELLID^E. NORM4LI4. Genus— LEPTASPIDIA. Generic character. Animal pear-shaped, flattened, ciliated along the margins; inner pair of antennae nearly one-third of the length of the outer pair ; legs terminated hy single acute dactylos ; pleon ovate, extremity entire ; uropoda lateral ; eyes obsolete. WE have established this genus for the reception of a minute animal, which differs in several of its characters from the rest of the family, but agrees with them in the dilated form of the body, with the margins of the segments ciliated, and the semi- circular form of the head, with the lateral posterior angles rounded. We have not observed the eyes in our unique specimen. The upper or inner antennae, which are most probably represented in our cut too wide apart, are nearly one-third of the length of the outer pair, which latter are about half the length of the animal, and appear to consist of three nearly equal-sized basal joints, and an articulated flagellum. The segments of the body are rounded and ciliated, gradually decreasing in width and length from the second joint. The legs are extremely short and slender, the anterior having the wrist and hand somewhat thickened, all terminating in a single slender and acute finger. The tail resembles that of the genus Munna, and is oval in shape, flattened and ciliated with a slight notch on each side beyond the middle, each impression bearing a small conical appen- dage (uropoda), the extremity being produced back- 332 ASELLID^E. wards, rounded and entire, resembling the minute ap- pendages existing on the telson of some Stomapod Crustacea. The outer pair of branchial plates shut together in the form of a flattened pear, divided down the centre : they cover the greater part of the underside of the tail. We have but little hesitation in classifying this genus with those that Professor Sars and his son have described under the name of Isopoda Remagantia, and for which Professor Lilljeborg has established the family of Mun- nopsidce, and which are pointed out by Professor Kroyer as having an affinity with the genus Munna. The typical form of the three posterior pairs of pereiopoda are developed into paddle-shaped organs, from which pecu- liarity the name of the group was given by Sars. But in the progress of his observations he found that others, assimilating to the type in most points, had not the three hinder pairs of legs so developed : hence, in his description of Macrostyles spinifera, he writes of these appendages as " Eorum structura ad natandum parum apta esse videtur " (vide Zoological Record, 1864, p. 295). The family is also described as containing animals having no eyes ; but we know that subterranean Crustacea are generally so, as agreeing with their peculiar habits ; but even in these, as far as our experience instructs, the organs are preserved, but reduced to a rudimentary condition. In the nearly-allied genus Munna, the eyes are large, and placed at the extremity of a fixed process. But in the other Asellidce the organs are less prominent ; and in all other respects we see nothing that can induce us, with the information that we possess, to separate this genus (and we believe also the Isopoda Remagantia) from the Asellidce. LEPTASPIDIA BKEVIPES. I SO POT) A. NORM ALT A. 333 ASELLIDJB. LEPTASPIDIA BREVIPES. Specific character. Cephalon large, semicircular, with a slight depression in the middle of the anterior margin, its posterior lateral angles rounded. First segment of the pereion with the fore margin emarginate, for the reception of the hind part of the head ; lateral margins of the segments of the body entire, rounded, and ciliated. Length, one-twentieth of an inch. WE are only acquainted with a single individual of the single species upon which we have established this genus, the specific characters of which cannot consequently at present be distinguished from the generic ones, and as our specimen was sent to us mounted for the microscope, we have not had sufficient opportunity of observation to allow us to detail the precise structure of the several parts. The antennae are implanted on the under surface 334 ASELLID^E. of the cephalon considerably within the margin. The anterior pair we take to be those that are figured pos- teriorly in our cut, the basal parts of which are seen through the transparent tissue. These have the joints of the peduncle, which we believe to be of the normal number, surmounted by a slender flagellum consisting of four articuli. The posterior pair of antennae are much longer, having the joints of the peduncle very long, and terminate in a slender flagellum, consisting of one long and four short articuli. The anterior pair of legs (first pair of gnathopoda) are moderately robust, and terminate in a hand of con- siderable prehensile power. All the other legs are slender and tolerably free from hairs. The pleon is pear- shaped, broader anteriorly : on each side, somewhere about two-thirds from the anterior margin, the posterior pair of pleopoda are implanted in the margin, these are fringed with two or three very fine cilia ; between this and the anterior margin the edge of the pleon is fringed with a delicate, serrated margin : so transparent is the structure, that it escaped our observation, when we drew the figure, that nine minute teeth were present. On each side of the pereion the hairs are connected together by an exquisitely fine fibrous membrane, that nearly reaches to their extremities. The animal lives in the mud ; two or three specimens have been taken by Mr. Robertson at Cumbrae, to whom we are indebted for it. JANIRA. 335 TSOPODA. ASELLID^. NOKMALI.t. Genus— JANIRA. (Leach.) ONISCODA. (Latreille.) V Generic character. Pereion serrated along the lateral margins ; pleon having all the segments coalesced into a single plate; covered, in the female, beneath with a large, flat membranous plate concealing the branchial feet ; and furnished at the tip with a pair of elongated bifid uropoda. Outer antennae as long as the animal. Dactyla biunguiculate. THIS genus has hitherto been known only by Leach's short and insufficient characters, which have been repro- duced by subsequent authors ; it is closely allied to Jfsra in its general character, but is at once distinguished by the pair of elongated styles at the extremity of the tail, each of which is terminated by a pair of narrow, slender plates, as in the genus Asellus. These styles are liable to be detached at a very slight touch, and hence many specimens of the animal are found destitute of them. They arise in a terminal emargination of the segment, but smaller than in Jcera, and having its postero-lateral margin finely ser- rated. In the males, the large terminal segment is furnished at its base, on the underside, with the male organ, which is narrow, flattened, nearly reaching to the extremity of the segment, and with its tip quadriden- tate. In the female, this terminal segment is entirely covered with a very thin membranous operculum, con- cealing the branchial apparatus. The outer antennse, 336 ASELLTD2E. in fully developed individuals, are longer than the whole animal. The flagellum is very long, and composed of a vast number of articuli, which are twice as broad as long, each of which appears to consist of three still more minute divisions; the inner antennae have on the second joint of the peduncle a small pointed articulate scale, the homotype on the large squamiform plate attached to the third joint of the peduncle of the inferior antennae in the macrourous Decapoda ; they are terminated by a slender multiarticulate flagellum, reaching beyond the middle of the long third joint of the outer pair. The fore legs (first pair of gnathopoda) are somewhat more robust than the following limbs, and in this pair the terminal ungues are unequal in size. The parts of the mouth resemble those of Jcera, except that in the mandibles we failed to detect the palpiform appendage, which may have been broken off. The labrum is rounded in front, with a deep central incision (fig. *). We have restored Dr. Leach's name of Janira to this genus, which Latreille, with complete disregard to the rules of priority in nomenclature, had changed to Oniscoda. The former name was published in the " Edinburgh Encyclopaedia," vol. vii., previous to 1814, as Dr. Leach himself, in his " Memoir on the Classification of the Linnaean Irisecta," read at the Linnaean Society in the early part of 1814, refers to his article in the " Edinburgh Encyclopaedia." In 1826 Risso, finding that the name Calypso, which in 1816 he had given to a genus allied to Galathea, had already been used by naturalists, proposed that of Janira in its stead, in the Errata to his " Natural History of the Crustacea of Nice ; " Latreille, however, overlooking the prior employment of the name Janira by Leach, rejected that name and proposed that of Oniscoda in its stead, in the *' Families Naturelles du ONISCODA. 337 Regne Animal," 1825,* forgetting that he had himself used that latter name for the tribe, of which Oniscoda is the type. * The effect of forgetting that he had himself used the latter name for the tribe of which Oniscus is the type, and this restoration of the name Janira to Leach's genus will be, that Risso's decapod genus, successively named Calypso and Janira, will require a third generic name. NEAR FOLKESTONE. VOL. II. 338 ISOPODA. NORM All A. ASELLIM. d JANIRA MACULOSA. Specific character. Ash -coloured, entirely covered with minute dark- brown dots ; segments of the pereion finely but irregularly denticulated along the lateral margins. Pleon serrated on the latero-posterior margin. Basal joint of the uropoda as long as the terminal rarni, of which the outer one is slightly longer than the inner. Length, from one-quarter to one-third of an inch. Janira maculosa. Oniscoda maculosa. LEACH, Edin. Enc. vii. p. 434. Trans. Linn. Soc. xi. p. 373. Suppl. Enc. Brit. i. p. 428. SAMOUELLE, Ent. Compend. p. 110. WHITE, B. M. Cat. Brit. Crust, p. 70. RATHKE, Nov. Acta. xx. p. 24. LATREILLE, Regue An. iv. p. 141. MILNE EDWARDS, Crust, iii. p. 151. WHITE, Pop. Hist. Brit. Crust. p. 184, pi. 12, f. 7. GOSSE, Man. Mar. Zool. 1, f. 244. THE body is flat and oblong, rather than ovate, in form, in consequence of the width of the head and tail. The JANIRA MACULOSA. 339 segments of the body are transversely channelled near the anterior margin of each, and each segment has its lateral margin marked with small incisions (that vary in speci- mens), giving a serrated appearance to the animal. The white upper surface is punctured and marked with minute dark -brown dots. The eyes are placed some- what on the disc of the head, instead of occupying its posterior lateral angles. The two basal joints of the peduncle of the posterior pair of antennae are short and stout ; the third is also short, but much narrower ; the fourth and fifth are long and slender, and the whole terminate in a long multiarticulate flagellum. On the second joint of the peduncle is a short, pointed, arti- culated plate ; this is tipped with three hairs. The first pair of legs are somewhat larger in the male than in the female, and have the carpus short and superiorly produced over the propodos ; the propodos is long, narrowly oval, and armed along the inferior margin with two or three short robust spines ; the dactylos is as long as the propodos, fringed with minute cilia along the concave margin, which impinges closely in its entire length against the inferior margin of the propodos, and has its extremity furnished with two curved ungues. The tail consists of a single plate ; it is flattened and nearly circular, with the latero-posteiior margins finely serrated, the extremity having but a small incision, the terminal styles (which are about equal to the entire tail in length, with the basal joint about as long as the two terminal branches) being affixed beneath the margin of the tail, so that their place of insertion is not seen from above.* We believe that the length of the antenna?, and the amount of serration at the sides of the body and tail, vary according to age and sex. z 2 340 ASELLID^. Colonel Montagu's typical specimens in the British Museum have served for our figures of this species. They were taken on the coast of Devonshire ; Mr. N. P. Cocks found it in crevices of rocks at Fahnouth. We also have it from Polperro, captured by Mr. Couch, from Berwick Bay, taken by the late Dr. G. Johnston ; the Rev. "W. Norman also obtained it on the Durham coast. ASELLUS. 1SOP ODA . NOR MALI A. Genus— ASELLUS . ( Geoffray. ) Generic character. Flagella of all the antennae multiarti- culate, lower pair more than half the length of the hody; eyes round and lateral ; pereiopoda uniunguiculate ; pleon with two long arid exserted bifid appendages. THE species of this genus have the body oblong, rather narrowed towards the head, with eight rather deep lateral incisions between the various segments of the body, which are depressed and slightly irregular on the upper surface, the sides being furnished with strong, irregular lengthened spines. The head is transverse, scarcely nar- rower than the body, the fore margin nearly straight, the eyes small, round, and quite lateral. The upper antennae about twice the length of the head, and very slender ; the lower antennae more than half the length of the animal, cylindrical, all the antennae having a multiarti- culate flagellum, which is very long in the lower pair. The segments of the body are nearly of equal size, each being marked with an impressed transverse line near the base. The fore pair of legs are rather short, robust (especially in the males), and terminated by a subcheli- ferous hand, with apical hook-like finger ; the three fol- lowing pairs of legs are longer, much more slender, and simply ambulatory ; and the three hind pairs of legs are gradually longer, all being terminated by a simple acute and curved finger. The tail consists of a large shield- like joint, with indications of two very short joints at 342 ASELLIDyE. its base, and with its extremity forming two wide but shallow emarginations, within which are affixed two long caudal appendages (or uropoda), composed of an oblong basal joint, supporting two elongated branches. On its under surface the tail bears two opercular plates, divided transversely by an articulation across the middle, which cover the branchial plates, and bear at the base a com- plex apparatus in both sexes. The only British species, and two others, natives of North America, occur in fresh-water ponds and lakes. The following vignette, taken for us by the Rev. J. M. Joass, of Eddestown, is a view of the Blasted Heath of Shakespeare, Forres seen in the distance, taken near a pool from which the Rev. George Gordon has sent us some very large specimens of Asellus aquaticus. THE BLASTED HEATH, FORRES. ASELLUS AQUATICUS. 343 1SOPODA. NORM All A ASELLUS AQUATICUS. Specific character. Upper antennas reaching to the extremity of the peduncle of the lower ; flagellum of the lower twice the length of the peduncle. Pereion of a greyish colour, mottled with paler markings ; pedun- cle of the caudal appendages nearly half the length of the slender terminal subequal filaments. Length of the male, nearly half an inch ; female, much smaller. Ouiscus aquaticus. Cymothoa aquatica. Asellus aquaticus. LINN. Syst. Nat. ii. p. 1061. ROEMER, Gen. Ins. pi. 30, fig. 12. FABRICIUS, Ent. Syst. ii. p. 505; Ejusd. Suppl. p. 303 (Idotea aq.). GEOFFROY, Ins. Paris, ii. p. 672, t. 22, f. 2. OLIVIER, Enc. Meth. iv. p. 252. LEACH, Trans. Linn. Soc. xi. p. 373. GUERIN MENEVILLE, Icon. E. An. Crust, t. 31, f. 3. SAMOUELLE, Ent. Compend. p. 110. WHITE, B. M. Cat. Brit. Crust, p. 69; Pop. Hist. Brit. Crust. p. 230, pi. 12, f. 6. 344 ASELLID^. Squilla asellus. DE GEER, Ins. vii. t. 31, f. 1 —20. Asellus vulgaris. LATREILLE, Hist. Nat. Crust, et Ins. vii. p. 359, t. 58, f. 1. DESMAREST, Cons. Crust, p. 314, t. 49, f. 1, 2. MILNE EDWARDS, Crust, iii. p. 146. CUVIER, R. An. (edit. Crochard) t. 70 bis, f. 1. Entomon hieroylyphicum. KLIN, Remarq. s. 1. Crust, fig. 5. THIS is a very common animal, occurring in fresh-water ponds and ditches throughout the kingdom. The male is much larger than the female. The head is about half the size of the following segment ; its underside is nearly covered by the large outer pair of foot-jaws, which con- sist of an oblong flattened basal joint (furnished on the outside, at the base, with a large semi-oval plate, Regne An. Ed. Crochard Crust., pi. 70 bis9 fig. 1 a, and Treviranus Verm. Schr. t. xi. fig. 59 a, a), and five short terminal joints, of which the first is produced into a lobe at its inner extremity, and the last forms an acute finger-like joint. The mandibles (Treviranus o. c. fig. 63) are armed on the inside with a strong, horny tooth, and on the outside with a three-jointed palpiform appendage. The inner maxillae are described by the same author (fig. 60) as only having two terminal setose lobes, and the outer (fig. 61) as formed of two lobes, the inner one much more slender than the outer. The bilobed labium (fig. 62 z) lying between the base of the man- dibles, is described by Treviranus as the third pair of maxillae. The ventral surface of the segments of the body, in the males, is marked with strong transverse corrugations ; in the female, it bears the large ovigerous sac, within which the young are developed. The male, as is well shown by Treviranus o. c. fig. 65 p. and 66 z, is fur- nished with a pair of small and narrow curved horny lobes in the middle of the hinder segment of the body, ASELLUS AQUATICUS. 345 on its underside, followed by a pair of small crustaceous sac-like appendages, constricted (ib. fig. 67 p. and De Geer, vii.pl. 31, fig. 12 e, e), which partially conceal a bi- partite, complex, horny apparatus, each portion consisting of a large basal joint (partly visible in the upper part of our figure, P), which supports two small knob-like ap- pendages, the innermost of which is armed with a small horny spur, directed backwards (De Geer, fig. 13 x, and Treviranus, fig. 67). This apparatus was first very carefully described and figured in detail by De Geer, and sub- sequently more satisfactorily by Treviranus. In the female, this apparatus is replaced by two small semi-oval plates, strongly ciliated along the terminal outer edge, which rest upon the base of the outer pair of branchial plates, the latter being divided into two nearly equal portions, as in the male. The following excellent account of the habits of this animal is given by Sir J. Dalyell, in his fine work on the " Powers of the Creator" : — " The species abounds in remarkable profusion in a pond at Red Braes, in the immediate vicinity of Edin- burgh. None exceed six lines in length, and little more than half a line in breadth. It feeds upon vegetable matter exclusively. The leaves of the beech in decay are preferred, and in such parts of the pond as these are most abundant, there the Asellus is most numerous. The animal does not generally swim, it runs freely and expeditiously over the decaying leaves. " The breeding season extends through several months of the year. The ovarian pouch occupies the under surface of the thorax and abdomen, and contains about forty ova. Many of the young, very minute and almost white, recently hatched, were running about over and under the leaves on the 2£iicl May. The young animal 346 ASELLID^E. is about half a line long, and transparent under the microscope. " The young in one instance were observed to be hatched during the week previous to the 22nd July, but in one year each of these specimens had a cluster of white ova on the thorax in the middle of September. " The posterior extremity of the young is proportion- ably more obtuse than in the parent. Further, unless it be immediately or speedily consequent on production from the ova, they do not seem to undergo any conspicuous metamorphosis. " Exuviation is less frequent here than in many other crustaceans. The integument, however, separates in two portions, which are nearly white. " This is an extremely pacific, tranquil creature, always seeking shelter. Specimens have survived many months when kept in confinement." The development of the eggs and young of this species has been carefully investigated by De Geer, in his great work on Insects, and more recently, in greater detail, by Rathke,* from whose elaborate series of illustrations the accompanying figures have been selected. The eggs having been discharged from the oviduct, are entirely destitute of any trace of germ, and are retained and hidden beneath the four pairs of large, slender, and semi-transparent scales attached to the under surface of the body of the female, where the young are disclosed, and remain until they have assumed a form similar to that of their parents. Our first figure repre- sents the egg in its early state, filled with the yolk and enclosed in a thin chorion. r Abhandlungen zur bildungs und entwickelungs Geschiehte des menschen mid der Thiere. Liepzig, 1832, 4to, Erster Theil, p. 3 tab. 1. Translated in Annales Sci. Nat., 2 ser. Zool. torn. 2. ASELLUS AQUATICUS. 347 EMBRYONIC DEVELOPMENT OF ASBLLUS AQTJATICUS. Iii figure 2, the egg is further advanced, showing the molecules of the head, and one of the external lateral appendages. In figure 3, the embryo is seen in front, showing the rudiments of the two pairs of antennae, labrum, five pairs of mouth-organs, and the two lateral external appendages. Figure 4 shows the embryo a little more advanced, and figures 5 and 6 the same, with the body stretched out and seen dorsally and laterally, exhibiting the eyes, segments of the body and tail, the latter figure representing the antennae thrown backwards laterally, and the rudimental legs. At this period the enclosed animal does not ex- hibit the slightest voluntary or involuntary movements, and Rathke consequently regards the Asellus as emerg- ing from the egg in a more imperfect state than any other articulated or vertebrated animal. At figures 7 348 ASELLID^:. and 8, the embryo is now nearly arrived at its full development, the legs exhibiting traces of articulation, and the lateral appendages having lost their trilobed ap- pearance ; the mandibles, two pairs of maxillae, foot, jaws, and branchial plates, and the terminal appendages of the tail are visible in figure 8 ; lastly, in figure 9, the embryo is seen in its final stage, with the large lateral antennae articulated, and the lateral appendages entirely lost. In figures 6 and 9 it will be observed that there are only six leg-bearing segments, and six rudi- mental pairs of legs, whilst there are seven segments and as many pairs of legs in the fully developed animal ; Rathke affirming that l( le dernier de ces anneaux et sa paire de pattes ne se forment qu'en peu de terns apres la sortie du jeune de la cavite incubatoire ' of the mother ; he, however, asserts that the wanting seventh segment is produced by the division into two parts of the sixth segment before the first moulting of the ani- mal, but admits that the formation of this last pair of legs " m'est restee assez obscure," partly because it is effected very rapidly, and partly because the other legs, being long, cover all the hind parts of the body.* We have ourselves examined the earliest stages of these animals, and our observations agree with those of Rathke, except that in the early embryonic condition the lateral appendages appeared to us to be entire, with a rounded terminal knob, instead of being tripartite, and that in the state corresponding with that of our lower right-hand figure, the upper pair of antennae are free, as in figure 9, and that the external sac-like appendages were associated with the hepatic lobes. * This circumstance is of considerable importance, viewed in connection with the question of the number of legs in the early stages of Entoniscus and Cryptolhiria, (Liriope) . LIMNOR1A. 349 I SOP ODA . A SELLID^E. NORMALIA. Genus— LIMNORIA. (Leach.) Generic character. Oblong-ovate, depressed ; antennae sub- equal, cylindrical, not longer than the cephalon. Pereiopoda nearly alike, slender. Pleon six-jointed. Branchial plates naked. Terminal segment large, semicircular, with a lateral appendage on each side bearing two terminal slender styles. THE small animal which forms the type of this genus is oblong, rounded in front and behind, and sub- depressed. The head is short and round, with the eyes wide apart, composed of but few facets. The antennae are of nearly equal length, being scarcely longer than the head, and terminated by a bristly pencil of hairs, the upper pair composed of three small joints and a small ex- articulate flagellum, and the lower pair also composed of three joints, with a small articulated flagellum. The outer foot-jaws consist of a long basal joint, closely united to the following, the inner apical angle of which is con- siderably dilated, produced and setose ; the four following joints are also short, with their inner angles similarly pro- duced. At the base is attached an elongated triangular plate ; this plate is developed to its fullest extent in the Idoteida. The mandibles are elongated, flattened, horny, broadly truncated at the extremity, and furnished with a triarticulate palpiform appendage. The first pair of maxillae consist of two very delicate elongated plates, the inner one being the more slender and curved; both are setose at the tip, but the inner has, moreover, a strong curved spine at its inner extremity. The second pair of 350 ASELLID.E. maxillae are also very delicate, furnished with three oblong-ovate terminal plates, setose at their extremities. The legs are short and slender, all being formed nearly alike, the four anterior ones being, however, rather more robust and tuberculated on the basal joints, all terminat- ing with a small slender curved finger. The tail consists of six segments, of which the four basal ones are short and equal, with the posterior margin entire ; the fifth has the posterior margin irregular, and the sixth is large, semicircular, flattened, with a slight central ridge; on each side it bears a lateral appendage, of which the basal portion is nearly square, with the outer margin notched, and terminating in a strong, curved, movable spine ; the apical portion forms a slender style, with strong bristles at its extremity, which appears to be separated into a minute articulation. The ovigerous pouch of the female consists of four pairs of scales, affixed to the middle segments of the body, and the tail is furnished on its underside with six pairs of scale-like, branchial plates, forming three rows, which are naked and of equal size. These plates are received, as in the Splicer omidce, in a cavity formed by the excavation of the underside of the caudal segments. In this respect, and especially in the segmentation of the pleon, the genus is removed from the remainder of the Asellidte; indeed, Dr. Leach formed it into a distinct race in his great family Cymothoadce, which also included the Serolida, JEgidce, and Sphceromidce. The whole of the dorsal surface is covered with stiff, pinnated hairs, amongst which numerous minute para- sites, somewhat like Echinorhynchi and Acari, are con- stantly to be seen. They even infest the branchiae. LIMNORIA LIGNORUM. ISOPODA. NORM All A. 351 ASELLID^E. * V : LIMNORIA LIGNORUM (THE GRIBBLE). Specific character. Entirely covered with small, setose hairs. Lower an- tennas not longer than the head. Terminal segment of the tail entire, rounded, and flattened, with a slight central dorsal carina, and the lateral margins raised. Length, about a line and a half. Cymotfioa liynorum. RATHKE, Skrivt af Naturh. Selsk, vol. 101, t. 3, f. 14 (1799). Limnoria lignorum. WHITE, Pop. Hist. Brit. Crust, p. 227, pi. 12, f. 5. Limnoria terebmns. LEACH, Diet. d. Sci. Nat. art. Cymothoadees, Edinb. Enc. vii. p. 433. Trans. Linn. Soc. xi. p. 371. Suppl. Enc. Brit. 1, 428. DESMAREST, Cons. Crust, p. 312. SAMOUELLE, Ent. Compend. p. 109. COLD- STREAM, in Edinb. New Phil. Journ. xvi.* p. 316, t. 6, f. 1—16. HOPE, Trans. Ent. Soc. Lond. 1, p. 119. W. THOMPSON, Edinb. New Phil. Journ. xviii. p. 127. MILNE EDWARDS, Crust, iii. p. 145. WHITE, B. M. Cat. Brit. Crust, p. 68. GOSSE, Man. Mar. Zool. 1, fig. 242. WESTWOOD, in Gar- dener's Chronicle, 1849, p. 388, fig. annexed. * This and the preceding plate are erroneously lettered u vol. xvii." 352 ASELLID.E. THE GRIBBLE is one of the most destructive creatures to be found amongst the whole of the articulated animals, burrowing into the wood of marine erections, such as piers, piles, and other works of public utility. Being the only known species contained in the genus, its leading characters have been detailed above, and in the generic description. The male is about one-third larger than the female. In general, not more than seven, or at most nine, young ones are found within the incubatory pouch. When the animal is alive, it contracts itself almost into a ball, thus confirming the relationship of the genus to the Spharomida. They are able to live at least a fortnight within the wood, taken out of the water and placed in a dry room. Each of the eyes is composed of seven or eight blackish facets, one being in the centre. The legs are articulated just beneath the sloping lateral margins of the body, and being partly folded beneath the pereion, a small portion only of each is seen when the animal is in motion. The longest are the first and fifth pairs; the legs of the second segment are shorter and thicker than those of the first, the third and fourth pairs being similar to the second ; the fifth pair is more slender, and the sixth and seventh pairs resemble the fifth, but are rather smaller. The terminal finger is, in all the legs, single and somewhat hooked. Dr. Coldstream describes a peculiar organ situated within the cavity of the tail, behind the branchiae, con- sisting of two vesicular bodies of an oval form, attached to a common peduncle. They were always found filled with numerous dark-coloured granules, of an irregularly round shape, which could not be detached from the sub- stance in which they were embedded by tearing it up. They exist in both males and females. The animal creeps but very slowly, backwards as well as forwards, appearing LIMNORIA LTGNORUM. 353 to drag itself along. It turns rapidly, using chiefly the caudal plates, which it uses as oars ; sometimes also it propels itself by a sudden movement of the tail, back- wards, to the distance of an inch or more, through the water. It appears that, notwithstanding the extent and im- portance of its ravages upon structures, affecting the interests of mankind in a very extensive manner, it was not noticed until about the year 1811, when Dr. Leach announced it, as a new and highly interesting species, sent to him by Robert Stevenson, Esq., the celebrated engineer, and as occurring in the greatest abundance at the Bell Rock lighthouse on the Scotch coast, erected by that gentleman, burrowing into the old woodwork, which it perforated in a most alarming manner, entering into it to the depth of several inches by boring in every direction, generally in straight lines, avoiding, however, the knots of the timber, round which it works. Many kinds of wood, including old oak, are devoured by the Limnoria, although it was generally found in other timbers, especially Mernel fir. Mr. Stevenson saw it attack oak, black-birch, and other woods ; indeed, teak was the only wood exposed to its ravages which was not perforated. Its mode of attack is very similar to that of the common Anobiutn in the timber of houses, &c., which is so often mistaken for dry rot, the chief difference being that the action of the waves wash away the outer and harder annual layers, in consequence of all the soft intervening spaces being eaten away, whilst the inner ones, as well as the knots of the branches, stand out in relief — consequently the surface of the wood soon becomes gradually rotten and reduced in its dimensions. It is by means of its mandibles that it forms its burrows in the wood, which evidently forms its support, VOL. II. A A 354 ASELLUXE. as the stomach is found filled with minute ligneous par- ticles. The burrows are about one-fifteenth of an inch in diameter ; they are cylindrical, and perfectly smooth on the inside. We must refer the reader to Dr. Coldstream's valuable memoir (from which most of the preceding details of the habits of the species have been derived) for an account of the injuries committed by these little depredators in various parts of the Scottish coast ; as well as to Mr. Thompson's memoir, in the 18th Volume of the " Edin burgh New Philosophical Journal," wrhere numerous Irish localities are recorded, and to Mr. Albany Han- cock's memoir in the " Newcastle Naturalists' Trans- actions." Mr. Hope's suggestions in the " Transactions of the Entomological Society," vol. i. p. 119 and xxxiv., must also be referred to for their practical character. It was observed by Mr. Spence, at Bridlingtori Bay, near Hull, and Dr. Moore stated in " Charlesworth's Magazine of Natural History," that its injurious effects had been observed for forty years in Plymouth Harbour. Through the kindness of the superintendent. Admiral Drummond, we have recently had the opportunity of examining into the extent of the depredations of this little creature on the submerged timber in the Royal Dockyard at Devonport. It is the opinion of Mr. Moore, the able and intelligent master shipwright, who has had the opportunity of ob- servation extending over thirty years, that the ravages of the gribble in this dockyard is considerably less than it was at the early part of his career. But this appeared to us to be more the result of suc- cessful attempts in the great care and ability shown in protecting the timber from the action of the animal, than in the decrease of this creature in the localitv. LIMNORIA LIGNOKUM. 355 The means taken to protect the woodwork are of several descriptions, viz., copper sheathing ; iron nails closely studded ; (the ferruginous oxide that the action of sea-water produces, impregnates the wood, and forms a protective iron crust all over the surface ;) creosote and coal-tar are likewise used, and it is the opinion of Mr. Moore that all timber that can be smeared over once a year, is effectually freed from the ravages of the Limnoria. The action of these animals is more or less rapid, according to circumstances. Pinewood they appear to destroy about the rate of one- quarter to half an inch in a year : of course this must be less rapid during the first year or so, and more rapid after several years, for the numerical increase of animal life must be greater in proportion to time. We find that that portion of the pine framework that supports the hull of the Robust frigate, that was commenced being built on the 31st of October, 1859, and is submerged at every tide, has been eaten in many places from two to three inches, while an inspection of the pine scaffolding round the half-built fort just within the Plymouth breakwater and harbour, erected between three and four years, shows us that the extent of the depredation amounts to from three-fourths of an inch to an inch and a half, according to the nature of the wood and its freedom from any pro- tecting influence. The little animals invariably choose the softer places, shunning the knots and hard lines of wood that longitudinally connect one knot with another. They likewise avoid every part of the wood that had been impregnated with iron, sometimes for several inches round the place where a nail or bolt had been driven. Oak they attack not so readily as pine, but still the former gradually falls before their persevering action, the A A 2 356 ASELLID.E. softer or more sappy portion disappearing more rapidly than the more solid parts. Thus it would appear that it is necessary that all timber mast be somewhat softened by the water before they commence their depredations. We have been indebted to Mr. H. Pownall for speci- mens of the injured timber, and individuals from the Southampton Water, extending to woodworks a mile up the Itchen river. It appears to be very general all round our coast. It is abundant in the river Dee, and the piles supporting the rock lighthouses at New Brighton are drilled by them. The late Mr. W. P. Cocks found them also in wood cast on shore at Falmouth, and the Rev. A. M. Norman has sent it us from the Shetlands. ISOPODA LIBERATICA, IT. 357 ISOPODA LIBERATICA.— Sub-tribe II. THE animals comprising the second sub- tribe of the Isopoda Liber atica (which is equivalent with the family Icloteides of M. Milne Edwards) differ from the general form of the order in the greater elongation and paral- lelism of the body, which is more or less abruptly trun- cated at each extremity. In the most extreme forms the body is quite cylindrical, resembling that of the larvae of certain Lepidopterous insects (Geometra), even in its peculiar movements and position when at rest. The eyes are large and lateral, the anterior pair of an- tennse are very short, and inserted above the posterior pair, which are considerably — occasionally very much — elongated. The mandibles are short, robust, and horny, with a strong denticulated apical incurved tooth, below which, on the inner margin, is a smaller denticulated and movable tooth : these organs are destitute of a palpiform appendage. The outer foot-jaws have the second joint produced into an elongated plate, ciliated at the tip with a hook in the middle of its interior margin ; the four terminal joints are variable in size, the fourth in Idotea being large and oval, whilst it is very small in Arcturus. The legs vary both in size and arrangement, the four anterior pairs in Arcturus being very slender, ciliated, and directed forwards, whilst the three posterior pairs are short and very robust, and directed backwards ; whilst in Idotea the legs are nearly of equal size and character, the three anterior pairs being directed forwards, and the four 358 ISOPODA LIBERATICA, II. posterior pairs backwards. In none of the groups are the fore legs terminated by a didactyle claw. The prin- cipal character of the tribe consists, however, in the structure of the tail and its appendages. This part of the body consists of one large caudal shield, destitute of lateral appendages, of which one or more of the anterior segments exhibit evidences of being more or less im- perfectly soldered together, whilst the branchial plates are arranged in five pairs, entirely closed over by the outer, that is, the first or anterior pair of pleopoda, which shut together like the two divisions of a cupboard door, and which plates have a transverse division near the ex- tremity. The British genera included in this tribe constitute two families, Arcturida and Idoteicke, well distinguished by the structure of their legs, which has induced Mr. Dana to remove Arcturus from this division of the order, and arrange it among his Anisopoda, a mode of distribu- tion which appears to us unnatural. Mr. Dana has, moreover, established an additional family in the sub-tribe, under the name of Chatilidn A . SPUJBROMIDA. NORMAL1A. Genus— CYMODOCEA. (Leach.) Generic character. Not capable of being completely rolled into a ball. Pleon very rugose, deeply excavated at the tip, with a lobe or tooth in the middle. Uropoda with the plates elevated obliquely, so as not to shut under each other, the inner plate being a process of the peduncle. THESE species are easily distinguished by the very rugose and setose segments of the tail, which is terminated by a deep notch, within which is a produced central plate or lobe. The body is more parallel at the sides than in Sphceroma, all the segments being simple. These charac- ters will at once distinguish the genus both from Sphceroma and Dynamene, which latter has been united with it as a second section by Professor Milne Edwards. The head is nearly as broad as the broadest part of the body. The flagella of both pairs of antennae are multi- articulate. The penultimate segment of the tail (forming the posterior margin of the consolidated basal mass) is prolonged in the middle and emarginate, the terminal segment bearing in the centre of its upper surface a com- pound tooth or spine, and the extremity of the tail is deeply notched, with a short horn or lobe in the middle of the notch. The foot-jaws have the intermediate joints prolonged on the inner margin, the extremity of the lobes thus formed being thickly ciliated. The lateral appen- dages of the tail have two small lobes, which are strongly ciliated with stiff short hairs, which also are thickly scattered upon the upper surface of the segments of the tail. 426 ISOPODA. NORMALIA. SPff^ROMID^E. CYMODOCEA TRUNCATA. Specific character. Pleon slightly granulated ; fourth segment with two small tubercles in the middle of the hind margin ; terminal segment with two larger dorsal tubercles, followed by a central oval, very setose tubercle, and three terminal spines, which are truncated. Length, five-twelfths of an inch. Oniscus truncatus. Cymodocea truncata. MONTAGU MSS. in Brit. Mus. LEACH, Edinb. Enc. vii. p. 433. Trans. Linn. Soc. xi. p. 303. Suppl. Enc. Brit. i. 427. Dictionn. Sci. Nat. xii. p. 343. SAMOUELLE, Ent. Compend. p. 108. DESMAREST, Cons. Crust, p. 297. MILNE EDWARDS, Crust, iii. p. 214. W. THOMPSON, in Ann, Nat. Hist. xx. p. 246. WHITE, B. M. Cat. Brit. Crust. p. 76. Pop. Hist. Brit. Crust, p. 246. GOSSE, Man. Mar. Zool. 1, fig. 236. OUR figure of this species is made from Dr. Leach's typical specimen preserved in the British Museum. It is very nearly allied to the following species, but it is much less rugose, and the form and size of the lateral appendages of the tail are different in the two species. CYMODOCEA TRUNCATA. 427 The body is somewhat cylindrical, with the sides nearly parallel. The entire length of the animal is about two and one-fourth times the width of the middle of the body. The antennas are short, the inferior being about as long as the breadth of the head ; the superior have the basal joint (omitted in our upper left-hand figure) strongly punctured. The tail has the upper surface irregular and setose. The basal portion has the middle of the posterior margin extended backwards, and emar- ginate, with two small tubercles near the angles of the emargination. The large terminal joint has two large oval setose tubercles in the middle of the upper side, followed by a slightly convex lobe, on which the bristly seise are set in a diverging manner ; and the extremity of the joint is armed with three flat truncated spines. The lateral appendages of the tail do not close as in the Sphtfromce, so as to form a convex shield, but are carried obliquely upwards ; the inner division is small and obliquely truncate, with the entire margin thickly set with strong bristles, and the outer division is consider- ably larger and oval in form, but with the outer angle subacute. The inner portion of this outer plate is par- tially folded when at rest beneath the inner plate. This species was taken by Montagu and Leach on the Devonshire coast ; but very sparingly. The Rev. A. Norman dredged it in Lamlash Bay, in the Isle of Arran, and found it under rocks at low water at Herm; and the late Mr. W. Thompson took it in Belfast Bay, at Rock- port, in April, and Mrs. Hyndman on Cultra shore, in September, and Dr. Macintosh has sent it to us from St. Andrews. 428 ISOPODA. NORM ALIA. SPH^EROMID^E. CYMODOCEA EMARGINATA. Specific charade)'. Upper surface of the posterior part of the pereion, and especially also of the pleon, granulose, the latter sparingly clothed with short stiff' bristles, having two tubercles on the hind margin of the basal portion, and two larger in the middle of the last segment, which has an oval lobe in the deep apical notch. Length, nearly half an inch. t'l/iiiodocca emaryinata. LEACH, Dictionn. Sci. Nat. xii. p. 343. DESMAREST, Cons. Crust, p. 296. MILNE EDWARDS, Crust, iii. p. 214. WHITE, B. M. Cat. Brit. Crust. p. 77. Pop. Hist. Brit. Crust, p. 246, pi. xiii. f. 7. THIS species is much more granulose on the upper surface than the preceding; the granules gradually in- creasing in size beyond the middle of the body. The head is very broad, and the eyes large. The basal joints of the antennae are punctured ; the terminal articuli of CmODOCEA EMARGINATA. 429 the flagellum of the upper pair (represented without the two basal joints in the middle right-hand figure), are fur- nished with flattened hairs at the tips. The foot-jaws have the three middle joints produced into long lobes, strongly ciliated at the tips, a portion of the cilia of the penultimate joint being set on at an obtuse angle to the rest. The basal portion of the tail has the middle of the hind margin extended backwards and emarginate, with a more or less distinct tubercle on each angle of the emargination. The middle of the upper surface of the terminal joint has two larger tubercles, followed by a depressed space, terminating generally in an erect tooth or obtuse point, the extremity of the joint armed with three obtuse points. The lateral appendages are very rugose and ciliated, the outer division nearly oval, but produced on the outside, at the tip, into a point; the inner division is narrower and curved, with the tip pointed. Dr. Leach took this species at Plymouth, under Mount Edgecombe. Mr. John Cranch found specimens, less strongly granulose, at Falmouth. We have received it from near Glasgow, taken by Mr. Robertson. The late Mr. W. Thompson found a specimen within the shell of a Balanus, affixed upon a Modiola vulgaris, from Belfast Bay. 430 SPH^ROMTD.E. ISO POD A . SPH^ER OMID^E. NORM A LI A. Genus— N^ESA. (Leach). White. N^SEA — M. Edwards.) Generic character. With the sixth segment of the pereion enlarged, and dorsally produced into a strong bidentate process. Pleou \vith the upper surface irregular and setose. Uropoda with the articulated ramus greatly elongated. THE dorsal surface of the body is smooth, but the sixth segment is slightly rugose, and is armed at its hind margin with two sharp processes extending over the tail, which has the upper surface irregular, with two large rounded tubercles in the middle : the outer plate of the lateral appendages of the tail is greatly elongated, and extends considerably backwards, whilst the inner plate is fixed, and transversely directed inwards, nearly meeting the corresponding division of the opposite appendage behind the middle of the hind margin of the tail. This peculiar structure of the tail and its appendages prevents the animal from rolling itself into a ball in the same manner as the Sph&rorfn».*..-v *s Microscopical representation of the texture of the dorsal tegument of Ligia oceanica. MS ONISCID.E. ISOPODA. ONISCID^B. NORM All A. Genus— PHILOSCIA. (Latreille.} ZIA. (Koch.) Generic character. Ovate, sub-depressed. Cephalon rounded, not lobed. Inner antennae minute, conical. Outer an ten nee with cylindric joints, eight-jointed. COXOB of sixth segment of pleon obsolete ; first to fifth, narrow, linear. Uropoda entirely exserted ; basal portion quadrilateral, transverse. Kami elongate, pointed at tip ; outer terminating in a bundle of setae ; inner more slender, and extending beyond the middle of the outer ramus. IT is a curious circumstance that the animals of this genus, common as they are, and well described by Latreille and Zaddach, should have been unknown to Brandt, Lereboullet, and Milne Edwards, who have affirmed that the genus ought to be reunited to Oniscus, whereas it is in fact more nearly allied in several respects to Liyia. The typical species appears to have been figured by Koch under the name of Ligia melanocephala, which in his generic table he subsequently altered into the generic name of Zia, giving, however, fifteen joints to the antennae, the flagellum being represented as com- posed of ten articulations. The species are glossy, with the body flattened, and the head destitute of lateral or frontal lobes. " The inferior border of the frontal ring of the head is nearly straight across ; the transverse suture well marked, nearly on a level with the superior margin of the ex- ternal antennae, its superior margin curved, raised, and passing slightly beyond the frontal line of the cephalic PHILOSCIA. 449 segment, shutting out the orbit from the insertion of the external antennae, and a deep sulcus separating it from the external angle of the orbit ; the third ring being thus transverse and narrow. The second ring is nearly as deep as the third, and well marked ; the epistomal narrow, and formed of two triangles placed apex to apex. The orbits are open below and behind." — Kin ah an. The inner antennae are very small, conical, and three- jointed. The outer antennae are cylindrical and eight- jointed, the three terminal joints forming the flagellum, which is tipped by a small short articulus. The legs have the lower margin of the intermediate joints armed with bristles ; they are terminated by a very minute hook or finger, which is slightly bifid at its tip. The two anterior segments of the tail are not produced into exserted lateral angles, as is the case with the three following. They are, however, narrower than the ter- minal segments of the body. The terminal segment is triangular, with the sides slightly emarginate for the insertion of the caudal appendages, which are elongated, and have the basal portion uncovered ; the inner ramus of each is more than half the length of the outer. The species are found in dry moss, at the roots of trees, and under leaves and stones. They run with great quickness, and do not hide away from the light. They do not attempt to roll themselves up into a ball, but feign death when alarmed. VOL. II. G G 450 ONISCID/E. ISOPODA. NORM ALIA. ONISC1DJ1. PHILOSCIA MUSCORUM. Specific character. Smooth, shining ; front of the cephalon slightly arched in the middle. Terminal segment of the pleon broadly triangular, apex acuminated, sides straight. Uropoda with the outer division falciform ; the inner lobe scarcely more than half the length of the latter. Length, one-fourth to one-third of an inch. Oniscus muscorum. Philoscia muscorum. Oniscus sylvestris. Liyia melanocepliala. Zia melanocepkala. SCOPOLI, Entom. Carniol. p. 1145. CUTTER, in Journ. d'Hist. Nat. i. t. 26, f. 6, 7. COQUEBEET, Illust. Iconog. t. 6, f. 12. LATREILLE, Hist. Crust, et Ins. vii. p. 43. Gen. Crust, et Ins. i. p. 69. LEACH, Trans. Linn. Soc. xi. p. 375, Edin. Enc. vii. p. 406. Suppl. Enc. Brit. i. p. 428. SAMOUELLE, Ent. Compend. p. 111. KINAHAN, Nat. Hist. Rev. v. 4, 1857, p. 280, pi. xx. figs. 1-6; v. 5, 1858, pp. 194, 195, pi. xxi. f. 4. WHITE, B. M. Cat. Brit. Crust, p. 72. Pop. Hist. Brit. Crust, p. 235. (Not the P. muscorum of Lereboullet, which is an Oniscus.) FABRICIUS, Ent. Syst. ii. p. 397. KOCH, in Herrick-Schaffer Contin. of Panzer Ins. Deutschl. 162, 18 ; ibid. Deutschl. Crust. 22, 18. Ibid. sub. Ins. D. 180, 1, and D. Crust. 40, 1. PHILOSCIA MUSCORUM. 451 THIS species is smooth and shining, generally of a fulvous colour, with dark black patches and white spots. The head is transversely elliptical and arched in front, being destitute of any lateral or median lobe. The internal antennae are small and inconspicuous ; the outer antennas are cylindrical and setose. The tail is much narrower than the terminal segments of the body, with the last ring broadly triangular, its apex being acute, and its terminal appendages having the outer division elongate-trigonate, spinous along its lateral margins ; the inner lobe nearly as long as the latter. The species runs with great rapidity, and seeks the sunshine. It is widely distributed, and very common. It prefers dry rather than damp situations, under leaves, stones, and moss ; also near the sea-shore. It is found abundantly throughout the southern part of England. Professor Bell found it under stones at Cheriton, and observes in his manuscript notes — " I found it of every shade of colour, from rich black to reddish brown and light green. It is more active than any other species, and the crust is more tender, and easily injured." Add- ing— te I believe colour to be absolutely valueless as a specific character in the whole of the Oniscidce" Dublin, Wicklow, Meath, Wexford, Cork, Waterford, and Tyrone, have been recorded as Irish localities. 452 1SOPODA. NORM ALT. 4. ONISCID.E. ONISCID^E, PHILOSCIA COUCHII. Specific character. Smooth and glossy. Front of the cephalon nearly straight. Terminal segment of the pleon linear- triangular, with the apex obtusely truncate, armed with bristles, the sides slightly excavated. Outer ramus of the uropoda subulate-falciform ; the inner not more than one-fourth of the length of the former. Length, one-fourth of an inch. Philoscia Couchii. KINAHAN, Nat. Hist. Rev. vol. v. 1858, p. 195, pi. 23, fig. 4. THIS species was first described by the late Professor Kinahan, who gave the following characters of it : — " Body smooth, elliptical. Head somewhat rounded, nearly straight across the front ; beneath the orbits is a small lobe arising from superior margin of the antennal ring.* Internal antennae inconspicuous; external antennae hairy. Tige (flagellum) long and narrow. Abdomen (tail) nar- rower than the cephalo-thorax (body). Telson (last seg- ment) narrow, linearly triangular ; apex rounded and "In the new species the frontal border of the carapace (cephalon) is carried well forward, and passes down to the antennse, the superior antennal ring having its margin produced into a minute lobe beneath the orbit. This species fully proves the judiciousness of the separation of Philoscia from Oniscus." PHILOSCIA COUCH II. 453 fringed with stiff bristles, sides excavated. Posterior pleopods (uropoda) with the ischium (outer ramus) elon- gate, falciform, subulate. Accessory appendage (inner ramus) scarcely one-fourth the length of the ischium. In other respects as in Philoscia muscorum" The colour is lead-grey, and uniform to the naked eye. The species runs with agility, but does not roll itself up into a ball. It was discovered at Talland Cove, near Polperro, from whence we were returning accompanied by Professor Kinahan, who gives this account of its dis- covery : — " In returning home we took the cliff road, and at Talland Cove spent a few moments examining the supra-littoral zone (the tide being nearly full in). Here, as might be expected, Ligia oceanica, Porcellio scaber, Philoscia muscorum, and Orchestia littorea, were abundant ; but I was much pleased by also meeting with a Philoscia new to me, and also undescribed in the books. This I have named Philoscia Couchii, in memorial of one of the pioneers in the study of the zoological geography of England, and of a few pleasant hours spent in his com- pany. The species appeared abundant, and the following description of the spot where it occurred may probably aid others in finding it : — Having descended the hill from Polperro, you cross the stream which drains an extensive osier marsh. The road then turns up a narrow ferny lane into a very heavy hill. Instead of turning up this lane, keep straight on from the bridge, and a few yards brings you up at the foot of the cliff. Here, amongst the loose stones and sea-weed carried up by the high tides into the clefts of the slate rocks, in company with the other Oniscoids, and many Myriapods, Philoscia Couchii will be seen hiding among the shingle, and easily distin- guishable from P. muscorum, which also occurs, by its uniform colour." 454 ONISCID.E. I SO POD A . ONJSCIDJF. NORM All A. Genus— PHILOUGRIA. (Kinahan.) ITEA.* (Koch.) Generic character. Ovate, sub-depressed. Cephalon without frontal or lateral lobes. Outer antennae nine or ten-jointed, with the second joint cylindrical; terminal joints subulated. Coxse of first and sixth rings of pleon obsolete. Uropoda entirely exserted ; basal portion trigonate. Outer ram us elongate, pointed, and exserted obliquely. Inner narrow, extending beyond the middle of outer, pointed. THIS genus was first proposed by Zaddach, and subse- quently adopted by Koch under the name of Itea — a name employed by Linnaeus for a well-known genus of plants. Its description also was not sufficiently precise ; whence Professor Kinahan was at first induced to con- sider the native species as undescribed, both generically and specifically. For both these reasons we consider ourselves warranted in adopting the generic name pro- posed by the lamented Irish naturalist. The species are of comparatively small size, with the body smooth and shining. The limbs are armed with strong spines, generally arising from small conical tubercles. The structure of the front part of the head is nearly similar to that of Philoscia, but the lateral ridges around the insertion of the external antennae are somewhat more strongly marked. The outer antennae are entirely exposed at the base. The five basal joints constituting the peduncle are robust, spinecl, and gra- * Noin. Gen. Plantarum. — LINN. PHILOUGRIA. 455 dually elongated to the fifth joint. The flagellum con- sists of four or five slender joints, generally terminated in a small pencil of setse. The hody is elongate-ovate, and the tail is considerably narrower than the former, with the lateral-posterior angles of the second and three following segments pro- minent ; and the terminal segment is broad and truncate at its extremity, with the terminal caudal appendages (uropoda) of considerable size, and partially covered, with the basal portion, somewhat triangular, affixed in a notch in the underside of the posterior margin of the terminal segment. The outer ramus is long and acumi- nated, terminating in a seta ; the inner slender and acuminated, more than half the length of the outer. The species are very active, and reside in damp situa- tions, thus agreeing with Philoscia, 456 TSOPODA. NORM ALIA. h ONISCID^. ONISCID^. PHILOUGRIA RIPARIA. Specific character. Elliptical, smooth and glossy. Inner antennas very minute and inconspicuous. Outer antennas nine-jointed. Terminal segment of the pleon deeply emarginate on each side, truncate, triangular, with the extremity deeply emarginate. Length, three -twentieths of an inch. Itea rlparia. KOCH, in Cont. Panz. Ins. Deutschl. 162, 17 ; and Deutschl. Crust. 22, 17. Philouyria riparia. KINAHAN, Nat. Hist. Rev. vol. v. 1858, pp. 197, 198, pi. 23, fig. 1. Itea Icevis (?). ZADDACH, Syn. Crust. Pruss. p. 16. Philougria celer. KINAHAN, Nat. Hist. Rev. vol. iv. 1857, p. 281, pi. 22, figs. 1-4. THE colour of this small species is uniformly claret- brown, appearing under a lens to be beautifully marbled with white. It is distinguished by its elliptical outline, and by the terminal segment of the tail being deeply PHILOUGRIA RIPARIA. 457 excavated over the insertion of the posterior pleopoda or terminal appendages ; its middle portion is produced backwards, truncately triangular, and deeply emarginate at the tip. Under a lens the skin is found to be marked with minute semicircular incised lines, giving the appear- ance of a series of scales, as seen at Fig. H'. The outer antennae appear to us to consist of only nine joints, the flagellum consisting of only the four terminal articula- tions. This species appears to be widely dispersed throughout England and Ireland, although rare in the southern counties of the former. It has been taken near Dublin, Wexford, Cork, and Kerry by Dr. Percival Wright, and at Tyrone, Waterford, Portlaw, Kilkenny, and Wicklow (Prof. Kinahan). In Epping Forest and Chiselhurst, Kent ; also at Plymouth ; Polperro (in the gardens of the inn, not uncommon) ; Looe abundantly, among sticks by the river side. It is found in very moist places amongst all kinds of decaying matter, also amongst moist dead leaves, amongst wet ashes, and in moss, at the roots of trees. It runs with agility, buries itself deep in the ground, and generally congregates in numbers. It is very impatient of dry ness, soon dying 011 exposure to air (Kinahan). It feigns death when disturbed, but does not attempt to roll itself in the least. Professor Kinahan found it with ova and young from February to November. 458 ISOPODA. NORM All A. ONISC1DJ1. ONISCID.E. PHILOUGRIA VIVIDA. Specific character. Oval, smooth, glossy. Terminal segment of the pleon triangular, truncate, the extremity nearly straight, without any emargination ; above, deeply sulcated. Outer antenme ten-jointed. Colour brown, marked with small buff- white dots. Length, five-twentieths of an inch. Itea vivida. Philougria vivida. Junior (?) Itea nana (?). KOCH, in Cont. Panzer Deutschl. Ins. 180, 4 ; and Deutschl. Crust. 40, 4. KINAHAN, Nat. Hist. Eev. vol. v. 1858, pp. 197, 198, pi. 23, fig. 2. Kocu, Opp. cit. 180, 5, and 40, 5. THE general colour of this species is claret-brown, marbled with white when seen under a lens. It is of an oval form, smooth and shining, with the surface of the skin marked, in addition to the small fine curved scale- like appearance of the preceding species, with small scat- tered impressed dots or pits, as shown in Fig. H'. The PHILOUGRIA VIVIDA. 459 second joint of the outer antennas is produced into an angle at its inner extremity, and the flagellum consists of five slender articuli. These organs are destitute of the spines which distinguish the other species. The terminal segment of the tail is triangular, truncate at the ex- tremity, very nearly straight and deeply furrowed above, but not emarginate. The caudal appendages are trigono- subulate. Taken not uncommonly under stones and moss on hills at Portlaw, 'in the county of Waterford, by Dr. Kinahan, in great abundance in March, 1858, even in the midst of snow. It runs with great agility, and does not bury itself deep in the earth like Ph. riparia. 460 1SOPODA. NOR MALI A. ONISCIDJE. ONISCID^E. PHILOUGRIA ROSEA. Specific character. Ovate, scabrous, covered with small tubercles. Eyes small. Inner antennae conspicuous. Outer antennse with the flagellum slender, with apparently only four articuli, which are very difficult to detect except iinder a strong lens ; tipped with a pencil of hairs. Terminal segment of the pleon with the extremity truncated, straight. Colour reddish, with whitish spots and dorsal line. Length, three-twentieths of an inch. Itea rosea. KOCH, in Contin. Panzer Deutschl. Ins. 162, 16 ; and Deutschl. Crust. 22, 16. Pkilougria rosea. KINAHAN, Nat. Hist. Rev. vol. v. 1858, pp. 197, 199, pi. 23, fig. 3. THIS species is distinguished by its colour, which is of a clear minium-rose, with white dots, and with a white stripe down the median line, or (in specimens found in dark places) of a dead white, having a dark median line. The upper surface, except that of the posterior PHILOUGRIA ROSEA. 461 segments of the tail, is tuberculated, each tubercle emitting a minute seta at its top. The eyes are small, black, and conspicuous. The inner antenna? are very conspicuous, extending beyond the front, and consisting of three joints with the tip setose ; the outer antennas are composed of five joints, besides the slender flagellum, which consists of four articuli, terminated by a long brush of hairs ; the basal joints of these antennae are armed with strong bristles arising from small triangular lobes. The lateral angles of the head beneath the orbits of the eyes are strongly marked. The terminal segment of the body is flat above, with the extremity truncate, and armed with several strong bristles. We believe that this species has only hitherto been found in Mr. C. Spence Bate's courtyard and cellar, and that of neighbouring houses, at Plymouth, where it' is tolerably abundant. Its habits agree with those of the rest of the genus, but it appears to frequent more humid haunts. It feigns death, but does not attempt to roll itself up, and is not quite so active as the other species. 462 ONISCID^. I SOP 0 DA . ONISCID^E. NORM A LI A. Genus— PLATYARTHRUS. (Brandt.) Generic character. Flattened, broadly ovate, scabrous. Cephalon transverse. Lateral and frontal lobes strongly developed, arising from the anterior margin. Outer antennae apparently six-jointed ; second joint small ; third short, nar- rowed outwardly at its base ; fourth, ovate ; fifth, largest, broad, flattened outwardly, but narrowed at its base ; sixth, thin, pointed at the tip, with a slight indication of a joint at its base. Terminal feet with the basal portion large, exposed. Terminal portion as long as the basal, conical. Inner appen- dage slender, exserted. THE type of this genus is closely allied to Oniscus and Porcellio, but differs in its short flattened antennae, scabrous, perfectly opaque, white body, as well as in various minor structural details. The head has its anterior lobes arranged nearly as in Armadillo, being derived, according to Dr. Kinahan, from the cephalic, mandibular, or fourth ring of the head, and not from the third or second, i.e., the antennary rings. The third is but badly developed and small, but the distinction between it and the fourth ring is evident. The internal antennae are three-jointed and very minute ; the outer antennae are short but broad, flat, and scabrous, the fifth joint being much the largest, and dilated. We have not been able, with a powerful lens, to discover any articulation at the base of the ter- minal joint, as described by Dr. Kinahan, although a slight dilatation in the lateral margin near the base seems PLATYARTHRUS. 463 to indicate the soldering together of two joints in that situation. The segments of the body are moderately convex, with a narrow lateral margin. The legs are short, with the second and three following joints of nearly equal size, terminated by a small hook-like finger, having a small tooth on the inside near the middle. The mandibles are strongly elbowed in the middle and ter- minated with two compound teeth, and furnished with a curved and setose spine in the middle of the inner margin. (In our woodcut the mandible is represented as lying on its back.) The two pairs of maxillae are very delicate, almost membranous, and ciliated at the tips. The foot-jaws are oblong, flat, and coriaceous, each terminated by two small quadrate lobes, which are trun- cated at the extremity, where they bear one or two small spines. The articulation between the posterior appendages and the last segment of the tail is very remarkable ; the latter is destitute of the epimeral coxae, and the ring is continued beneath, terminating abruptly on either side in a rounded lobe ; so that the central portion of the body underneath is unprotected. The posterior pair of appendages are articulated to the anterior border of the inferior (sternal ?) part of the ring, a little within the ex- ternal lateral angle, by a well-marked ball-and-socket joint, so that at first sight it appears as though these appendages were derived from the penultimate and not from the terminal segment. The posterior appendages are exserted, the peduncular portion somewhat square, with the sides parallel. The outer ramus is nearly as long as the base, ovate, flattened, and pointed at the tip, where it is fur- nished with a minute filament. The inner ramus forms a slender filament, extending beyond the basal portion against the inner side : it is articulated near the base. 464 ISOPODA. NORM ALT A. ONISCID.E. ONISCIDJZ. PLATYARTHRUS HOFFMANNSEGGII. Specific character. Opaque -white. Upper surface of the animal scabrous, with compressed scale -like club-shaped prominences. Posterior margins of the segments sub-serrated. Length, one to one and three- quarters of a line. Platyarthrus Hoffmannseggii. BRANDT, Bull. Soc. Nat. Moscow, vi. p. 174, pi. 4, fig. 10 (antenna, absq. descr. specifica). HOGAN, in Nat. Hist. Rev. vi. p. 109. KINAHAN, in ditto, p. 127. Itea crassicornis (?). KOCH, in Contin. Panzer Ins. Deutschl. 186, fol. 5 ; and Deutschl. Crust. &c. 36, 5. THIS curious little species has much the aspect of a Porcellio ; it is, however, considerably broader in propor- tion to its size, the smallness of which, moreover, together with its opaque-white colour, broad short antennae, sub- terrestrial and ant-loving habits, well distinguish it. The head is broader anteriorly than posteriorly, deeply PLATYARTHRUS HOFFMANNSEGGII. 465 immersed in the first segment of the body, and very scabrous ; the lateral lobes are much developed. The antennae are scabrous, as are also the segments of the body, the epimeral base of the legs forming the lateral margins of the segments, with the posterior angles directed downwards ; the same part in the intermediate rings of the tail are also well developed ; the terminal segment is triangular, emarginate on each side, with a shallow pit on its upper surface, its posterior margin tuberculated, as are also the posterior appendages (uropoda). The species was first noticed as British by the Rev. A. R. Hogan, M.A., who found it in ants' nests at Lulworth Cove, near Weymouth, where he ^observed it in as many as thirty nests of the common red, yellow, and black ants, whilst about twice that number of nests in the neighbourhood were not found to be frequented by it. Previous to Mr. Hogan's discovery we had noticed the occurrence of these white Oniscidae in the nests of the common brown garden ant at Hammer- smith, but thought they were merely the young of some species of Porcellio. Since that time Mr. F. Smith has also found the species in the neighbourhood of London, and we have also again met with it in ants' nests in the neighbourhood of Stow Wood, near Oxford, in the early summer months, as also at Berry Head, near Torquay, where they were found by Master McGuire Bate ; and near Plymouth, taken by Mr. Brooking Rowe. VOL. n. H H 466 ONISCID/E. I SOP 0 DA . NOR MALI A. Genus — ONISCUS. (Linrweus.) Generic character. Ovate, sub-depressed. Cephalon with large lateral lobes extending outwards beneath the eyes. Outer antennae eight-jointed ; second joint dilated at the base ; seventh and eighth joints sub-confluent. Coxae of the first, second, and sixth segments of pleon obsolete ; third to the fifth, broad and curved, acute at tips. Terminal uropoda posteriorly exserted ; npical portion ovate, pointed at tip. Inner lobe linear, short, extending slightly beyond the telson, which is convex. THE species of this genus are typical of the family, commonly called wood-lice, and are distinguished from the other equally common species by having the ter- minal portion of the outer antennae composed of three joints, of which, however, the articulation between the last and preceding joint is less distinct than the pre- ceding. The Philoscia, which have also eight-jointed setose antennae, are distinguished at once from the Onisci by the narrowness of the segments of the tail and the length of its exserted terminal appendages. " The external angles of the superior margin of the third ring of the head are produced into a broad lobe, which covers over the origin of the external antennae ; it is then continued across, projecting slightly over the frontal line of the cephalic segment ; the transverse suture is well marked ; the second ring very narrow, almost obsolete. The lateral lobes are continued back- wards, and are separated by a suture from the external ONISCUS. 467 inferior border of the cephalic segment which completes the orbits." (Kinahan.) The structure of the mouth-organs is described under the typical species O. asellus. The first and second seg- ments of the tail are visible only in the middle of the dorsal surface, the lateral margins of the third segment (of which the posterior angles are produced backwards, and acute) forms a continuous line with the lateral margins of the last segment of the body. The terminal segment is also narrowed at its base ; and if we draw a line from its outer basal angles to the lateral angles of the two basal segments, we shall perceive that the lateral margins of the third, fourth, and fifth segments are pro- duced outside of this line, and are strictly supplemental appendages or lateral lobes. The extremity of the terminal segment is produced into a narrow and elongated point, its upper surface being convex, the basal portion of the terminal appen- dages extending to about half the length of this pro- duced joint, of which the apex reaches the middle of the outer division of the appendage ; the inner lobe of the basal portion is narrow and elongated, extending a short distance beyond the extremity of the tail. The species frequent damp situations, and have not the power of rolling themselves into a perfect ball, but attempt to do this in an incomplete manner, feigning death when alarmed. H II 468 ONISCIM. ISOPODA. NORM ALIA. ONISCUS ASELLUS. Specific character. Broadly ovate, sub-depressed, shining ; covered with smooth granules. Lateral lobes of the cephalon large, inclined backwards. Frontal line somewhat emarginate. Terminal segment of the pleon elongate- triangular, convex above. Intermediate segments of the pleon terminating in acute angles. Length, three and a half to eight lines. Oniscus aseUus. LINN., Syst. Nat. ii. p. 1061. DE GEER, Ins. vii. t. 35, f. 1. GEOFFROY, Ins. Paris, ii. t. 22, f. 1. LATREILLE, Hist. Nat. Crust, et Ins. vii. p. 42. LEACH, Edin. Enc. vii. 406. SAMOUELLE, Ent. Compend. p. 111. JOHNSSON, Syn. Framst. Sver. Onisc. p. 15. WHITE, B. M. Cat. Brit. Crust, p. 71. Pop. Hist. Brit. Crust, p. 234. Oniscus murarius. CUVIER, in Journ. d'Hist. Nat. ii. t. 26, f. 11. FABRICIUS, Ent. Syst. Suppl. p. 300. BRANDT and RATZEB., Arzn. Thiere, ii. t. 12, f. 7. BRANDT, in Bull. Mosc. vi. p. 182. MILNE EDWARDS, Crust, iii. ONISCUS ASELLUS. 469 p. 163. KINAHAN, Nat. Hist. Rev. vol. iv. 1857, p. 276, pi. xix. figs. 10, 11, 12, pi. xx. fig. 11, pi. xxi. tig. DA. BURCERSDIJK, Annotat. p. 50. SCHNITZLER, Onisc. Agri. Bonn. p. 22. THE upper surface of the animal is glossy and deli- cately punctured, as seen under a lens, the head and segments of the body being dorsally furnished with longitudinal raised spaces, leaving the posterior margin of each smooth. The head is received within a deep emargination of the anterior segment of the body, the anterior angles of which extend even in advance of the two prominent lateral lobes of the head. The inner antennae are minute and three-jointed, the terminal joint being the longest and most slender, with a slight setose notch near the apex. The outer antennae have the basal joint small, the second short, but broad and dilated at its base on the outside ; the fifth joint is the longest, the three terminal joints being much more slender, and not more than two-thirds of the length of the fifth joint (in our magnified outline figure, c, the articulation between the two terminal joints is much too strongly marked) ; the tip of the eighth or terminal joint is furnished with a minute spine. The labrum is membranous, and composed of two divi- sions, each of which is oblong in form, rounded at the extremity, where is a deep narrow notch or fold, the inner angle being somewhat more advanced, rounded off, and finely setose : the right-hand division is represented in figure lb'. The mandibles are strong and horny, oblong in form, strongly angulated on the outside, the apex being at right angles with the base, and terminated by a compound tooth, with three or four short curved spatulated bristles along the margin, the inner angle of which is furnished 470 ONISCID.E. with a strong curved bristle, acute at the tip. The inner maxillas are very delicate, and almost membranous, oblique at the tip, with two curved setose bristles, the base armed with two remarkable muscles. The outer maxillae are narrowly oblong and rather curved, setose at the outer margin, and spinose at the tip ; the foot-jaws are oblong, rounded on the outside, the external base armed with a strong triangular lobe ; the apex is divided into two parts, the inner of which terminates in several small teeth, and the outer in a movable finger-like lobe, articulated at its base. The legs are all cursorial, and are terminated by a foot having a small tooth on the inside. The branchial appendages on the underside of the tail are arranged in pairs, the inner angle of the apical margin being more or less extended backwards ; moreover, in the males, the second pair of these appendages are furnished at their base with a long style, dilated at its base, pointed, and slightly curved at its tip. The ter- minal pair of these limbs form the exserted biarticulated appendages seen on either side of the acuminated ter- minal joint of the tail ; the two divisions of the last pair are nearly equal in length, the middle of the outer division extending to the tip of the tail. The internal accessory lobe of the basal portion is slender, and extends rather beyond the tip of the last joint of the tail. The general colour of this species is of a light greyish brown or slaty lead, marked with blotches and spots of yellowish white or buff, of which the most conspicuous form a regular row on each side, parallel to the lateral margins of the segments, the margins being also pale with a dark spot: the dorsal spots are less distinct: a salmon-coloured variety, with dark patches, is stated by ONISCUS ASELLUS. 471 Professor Kinahan to be occasionally met with near the sea. This species is rarely found more than half an inch in length, but we possess a specimen, of unknown locality, measuring two-thirds of an inch. It is very common throughout England, Scotland, and Ireland, under decay- ing vegetable and animal matter, not only in damp, but in the dryest localities. It is also common near the sea. It was formerly used in medicine, and was supposed to cure agues, consumption, &c. It is commonly known under the vulgar names of Pig's-louse, Sows, Woodlouse, Millepede, or Carpenter. ONISCUS FOSSOR, Specific character. Oval, sub-depressed, covered with numerous rough granulations, which give it a powdered appearance. Cephalon convex. Lateral lobes moderate, rounded. Frontal line produced into a triangular lobe. Length, five lines. 0 ni 'sous fossor. KOCH, Dtsch. Crust, h. 22, n. 22 ; and in H. SCHAPFER, Contin. Panz. Faun. Ins. Germ. 102, fol. 22. KINAHAN, Nat. Hist. Rev. vol. iv. 1857, p. 277, pi. xxi. figs. 5, 6, 7. Oniscus muscorum. LEREBOULLET, Mem. Strasbourg, iv. p. 29. Porccllio tceniola. KOCH, Dtsch. Crust, h. 6, n, 2 ; and in H. SCHAFP. Cont. Panz. h. 139, n. 2 (var. ?). Oniscus tceniola. Ibid. h. 180, n. 20, note, and fig. 6 (var. ?). THIS species so closely resembles the preceding, that we have not considered it necessary to give a figure of it, which, indeed, without colours, would scarcely show its chief distinction, consisting in the much more 472 ONISOID/E. opaque upper surface of the body, which is finely punc- tured and furnished with the same kind of oblong- tubercles found in 0. asellus, but more numerous and closely arranged. The head also is more prominent. It is of a more uniform brownish-grey colour, although exhibiting the same kind of pale patches and rows of spots seen in that species. It also appears to be uni- formly smaller than O. asellus. We have adopted the reference to Koch's figure of Oniscus fossor, which Professor Kinahan states to be very characteristic, although the flag ell um of the antennae is only represented with two instead of three joints, as in the type of the genus. This species inhabits dry places under stones and dry leaves. It is more active than the preceding species. It has been taken in Epping Forest and Chiselhurst, Kent, and near Dublin and Wexford, in Ireland. Specimens are in the British Museum, as well as in the Stephensian Collection of Crustacea at Oxford, purchased by the Rev. F. W. Hope, the latter being named O. asellus ; and the Rev. A. M. Norman records it from Sedgefield, Co. Durham. PORCELL10. 473 ISOPODA. ONISOID^E. NORM A LI A. Genus— PORCELLIO. (Latreille.) Generic character. Ovate, sub-depressed. Cephalon with large lateral lobes. Outer antennae seven-jointed. Coxse of the second and sixth segments of pleon obsolete. Terminal uropoda with the basal portion triangular, flattened. Apical portion compressed, trigonate, exserted. Inner appendage small, curved, and trigonate, concealed by the last segment of the pleon, which is more or less concave on its upper surface. THE animals of this genus differ from those of Armadillo (which they resemble in having only seven- jointed outer antennas), in the form of the second joint of those organs, which is not furnished with a rounded lobe on the outside at its extremity — a peculiarity dependent on the different arrangement of the front part of the head, and the consequent manner in which these organs are disposed when at rest, the remarkable groove at the sides of the front of the head being here wanting. The late Professor Kinahan thus described the structure of the front of the head in Porcellio : — "External angles of the third antennary segment of the head more developed than in Oniscus, the superior margin raised into a lobe, which projects above the frontal line of the cephalic segment, and gives the head a trilobed appearance. This lobe, though sometimes badly marked (Porcellio pruinosus, Br. — P.frontalis Lereb., not Edw., for example), is present in all the species I have had an opportunity of examining." 474 ONISCIDJE. The inner antennae are very minute and four-jointed, the second joint in some of the species appearing to be formed of several minute rings. The outer antennae are seven-jointed, the basal joint also occasionally appearing as if formed of two portions. The base of the second joint is dilated ; the fifth joint is long and somewhat slender, being considerably longer than the two terminal joints united. The details of the mouth-organs are described under Porcellio scaber, and need not, therefore, be here given. The elongation of the terminal appen- dages of the tail, to a considerable length beyond its extremity, also distinguishes these animals from Arma- dillo, the inner lobe of the basal support being even occasionally visible beyond the terminal joint of the tail. ISOPODA. NORMAL I A. I'ORCELLIO SCABER. 47.5 ONISCIDJB. POHCELLIO SCABER. Specific character. Elongate-ovate, rugose. Lateral processes of the ceplmlon very prominent, with the external angle rounded. The middle pro- cess triangular. Last joint of the pleon ending in a sharp triangular point, deeply sulcated down the middle. Length, nearly half an inch. Porccllio scaber. LATREILLE, Hist. Nat. Crust, et Ins. vii. p. 45. Gen. Cr. et Ins. i. p. 70. LEACH, in Trans. Linn. Soc. xi. p. 375. Edinb. Enc. vii. p. 406. Suppl. Enc. Brit. 1429. SAMOUELLE, Eut. Comp. p. 112. DESMAEEST, Cons. Crust, p. 321. GTUERIN-MENEV. Icon. R. An. Crust, t. 31, f. 7. MILNE EDWARDS, Crust, iii. p. 167. CUVIER, R&gne An. (Edit. Crochard), t. 71, f. 1. KINAHAN, Nat. Hist. Rev. vol. 4, 1857, p. 277, pi. xxi. figs. 2 and 8. KOCH, in Cont. Panzer Heft. 180, n. 6 and 7. WHITE, B. M. Cat. Brit. Crust, p. 72. Pop. Hist. Brit. Crust, p. 237, pi. xiii. fig. 2. BRANDT and RATZEBURG, 476 ONISCID^E. Arzn. Thiere, ii. tab. 12, f. 1, 2, 3, 4. JOHNSSON, Syn. Framst. Sver. Onisc. p. 21. ZADDACH, Syn. Crust. Pruss. p. 12. BURGERSDIJK, Annot. p. 39. SCHNITZLER, Onisc. Bonn. p. 23. Oniscus granulatus. LAMARCK, Hist. Anim. sans Vertebr. v. p. 261. Porcellio dilatatus. BRANDT and RATZEB., Arzn. Thiere, t. 12, f. 6. BRANDT, Bull. Moscow, vi. p. 176. Oniscus asellus. FABRICTUS, Ent. Syst. Suppl. p. 300. Porcellio Brandtii. MILNE EDWARDS, Crust, iii. 168 (var.). Porcellio dubius. KOCH, in Cont. Panz. Heft. 180, n. 8. Porcellio affinis. KOCH, in Cont. Panz. Heft. ISO, n. 13 (var.). THIS species is at once distinguished by the entire upper surface of the animal being strongly marked with round and elevated tubercles. The lateral lobes of the head are very prominent, and rounded at the outer angles, whilst the central lobe is strongly produced and nearly triangular. The animal is more or less ovate in form, and moderately convex, with the posterior angles of the segments of the body moderately produced and pointed. The outer antennas have the second joint dilated internally at its base. The fifth joint is the longest, and the two terminal joints united are about two-thirds of the length of the fifth. The upper lip is formed of two flattened membranous plates, of each of which the outer apical angle is rounded, and the inner angle slightly extended, dilated, and setose. The right- hand division of this lip is represented in figure W '. The mandibles are horny, strongly angulated on the outside, the extremity being at right angles with the base, and armed with three teeth, which seen laterally are obliquely truncated. Below this, the inner margin of the mandible beyond the middle is armed with a complicated series of short horny teeth and bristles, the innermost of which is elongated and curved. The inner maxillae are delicate, and armed at the tip with two setose bristles ; the outer maxillae are large, oblong, setose on the outer edge, and PORCELLIO SCABER. 477 spinose at the tip. The foot-jaws are formed of a pair of large oblong plates, having an elongated horny sup- port on the outside arising from their base. The ex- tremity of each is furnished with a number of minute teeth, the inner ones arising from a distinct but very short lobe or division. The terminal appendages of the tail are robust, with the outer division triangularly ovate, and extending about half its length beyond the extremity of the telson or terminal segment of the tail, which ends in a sharp triangular point, having a groove along the middle of its dorsal surface, and which completely covers and conceals the elongated accessory plate of the base of the apical appendages. The colour of this species is uniformly of a greyish black or slaty grey, more or less strongly spotted with yellow ochre or whitish buff. A nearly uniform salmon- coloured variety also occurs, and it is very probable that others of the supposed species figured by Koch may be only varieties. In P. dubius of Koch, the pale spots are wanting, the uniform colour being blackish. In his P. qffinis there is a pale lateral line parallel to each side, running through the whole of the segments of the body. The species runs with agility, and partially rolls itself into a ball when alarmed. It has been observed feeding on living caterpillars, frequenting moist places where decaying vegetation is found, and even among sea-weed, in company with Ligia, &c. We have also found it partial to growing vegetables, and it appears to possess a strong partiality for nearly ripe wall-fruit. It is very widely distributed throughout England and Ireland. The female may be found with eggs contained in the ventral pouch throughout the year. 478 ISOPODA. NORM All A. ON1SCID/E. ONISCID^E. PORCELLIO D1LATATUS. Specific character. Very broad, depressed, rough, and granular. Lateral frontal processes very prominent, rounded at the apex, and concave. Median lobe obtusely triangular, moderately developed. Terminal segment of the pleon rounded at its apex, nearly flat above. Terminal plate of uropoda flat and broadly ovate, pointed at the tip. Length, five to seven lines. Porcellio dilatatus. BRANDT, Bull. Mosc. vi. p. 176. BRANDT and RATZE- BURG, Arzn. Thiere, ii. pi. 12, f. 6. BURGERSDUK, Annot. p. 44. KINAIIAN, Dublin Nat. Hist. Eev. vol. 4, 1857, p. 278. SCHNITZLER, Onisc. Bonn, p. 23. Porccllio scaber. MILNE EDWARDS, Crust, iii. p. 167. THIS species is ordinarily much larger than P. scaber, from which it is easily distinguished by its very broad form, and by the less scabrous surface of its body. The outer antennae are rather short, with the two terminal PORCELLIO DILATATUS. 479 joints of nearly equal length. The lateral lobes of the front of the head are large, and curved rather outwards ; they extend rather beyond the anterior angles of the •/ •- first segment of the body, which, together with the two or three following segments, are marked with rather oblique and slender lines and rugosities. The terminal segment of the tail has the sides of the apical half nearly parallel, and the tip itself rounded. It is of an uniform slaty-grey colour, with faint irregular pale lines and spots indicating the chief rugosities. It is found amongst decaying grass and straw, and appears to be extremely rare. It crawls very slowly, and partially rolls itself into a ball. It is very brittle in its texture, a touch causing the limbs to fall off. Specimens are preserved in the British Museum, found by Prof. Kinahan, from the neighbourhood of Dublin. 480 TSOPODA . NOKMALU. ONISClDyE. ON1SC1DJ1. PORCELLIO PICTTJS. Specific character. Slightly elongated, moderately granulated, upper sur- face glossy . Lateral lobes of the ceplialon very prominent, curved outwards and downwards ; the median lobe small and curvilinear. Terminal segment of the pleon triangular, acute at the apex, sulcated above. Length, about one-third of an inch. Porcellio pictus. BRANDT and RATZEBURG, Arzne-tlriere, ii. pi. 12, f. 5. Gonspect. Mon. Onisc. Bull. Mosc. vi. p. 176. MILNE EDWARDS, Crust, iii. 166. KIN AH AN, Dublin Nat. Hist. Rev. vol. 4, 1857, p. 278. JOHNSSON, Syn. Framst. Sver. Onisc. p. 22. BURGERSDLJK, Annot. p. 46. KOCH, Gout. Panz. Heft. 180, n. 18. KOCH, Cont. Panz. Heft. 180, n. 19. KOCH, Cont. Panz. Heft. 180, n. 17. ZADDACH, Syn. Crust. Pruss. p. 12 (?). Porcellio melanocephalus. SCHNITZLER, Onisc. Bonn. p. 24 (and KOCH ?). (Var.) P. serialis. (Var.) P. crassicornis. (Yar. 0 P. conspersus. FINELY-MARKED specimens of this species are amongst the handsomest of the British Isopods. The general PORCELLIO PICTUS. 481 form of the body is that of P. scaber, but the compara- tively small amount of granulation of the upper surface, with the short triangular terminal segment of the tail pointed acutely at its tip, will serve to distinguish it, independent of its coloration and marking. The head is entirely black and strongly granulated, the granules of the hind part of the head being arranged in transverse rows ; the ground colour of the remainder of the animal is that of yellowish clay. The anterior half of the first segment of the body has a black streak extending down the middle, on each side of which is a bright yellow patch, with a black spot on each side behind the eyes. These spots reappear in the following joints, the central black one being widened, and the yellow one on each side nearly forming a ring, enclosing a dark spot and some dark dots ; the lateral margins are yellow, with groups of black dots near the edges, and a sub- marginal black streak on each side parallel with the margin. The basal portion of the apical appendage of the tail is yellow, and the broad outer division black, with the tip pale. The outer antennae are dusky, the sixth joint being evidently longer than the terminal one. The several varieties above quoted, given as distinct species by Koch, vary in the greater or less clearness of the dark longitudinal stripes down the back ; in P. serialis these dark stripes alternate in nearly equal width with the intervening pale ground of the body, leaving in fact a pale central and two narrow streaks parallel with the sides of the body, together with a broader or less clearly defined one on each side of the dark lines at the edges of the central pale one. In its general form and appearance it resembles Oniscus fossor, from which it however differs in being far more glossy and variegated in colour. VOL. IT. I J 482 ONISCID.E. It appears to affect dry situations, such as the rubbish in old ruins, and under dry leaves. It runs with great agility, and does not roll itself into a ball. The neighbourhood of Dublin and Belfast in Ireland, and Chiselhurst in Kent, in England, have been recorded as the localities of this species ; in the latter situation it was found in chalk pits. THE KERRY ANCHOR. FOR CELL TO L/RVIS. ISOPODA. NORM A LI A. 483 ONISC1DJB. PORCELLIO L&VIS. Specific character. Very convex, smooth. Lobes of the sides of the front of the cephalon slightly prominent, small, and rounded at the outer angle ; middle lobe very short. Terminal segment of pleon rounded at the tip, deeply silicate down the middle. Uropoda considerably elongated. Length, three-quarters of an inch. Porcellio Icevis. Cylistlcus laivis. LATREILLE, Hist. Nat. Crust, et Ins. vii. p. 46 ; Gen. Cr. et Ins. i. p. 70. LAMARCK, Anim. s. Vertebr. t. 5, p. 154 (Oniscus I.}. MILNE EDWARDS, Crust, iii. p. 169. KINAHAN, Nat. Hist. Rev. vol. iv. 1857, p. 278. WHITE, B. M. Cat. Brit. Crust, p. 72. Pop. Hist. Brit. Crust, p. 237. JOHNSSON, Syn. Framst. Sver. Onisc. p. 27. ZADDACH, Syn. Crust. Pruss. p. 13. SCHNITZLER, Onisc. Agri Bonn. p. 25. THIS is the largest British species of the genus, and is well distinguished by the smooth upper surface of the animal, the small lateral lobes of the face, and the great i i 2 484 ONISCLIXE. length of the two terminal appendages of the tail. Heir Schnitzler has, indeed, proposed to form it into a separate genus, Cylisticus, on account of the convexity of the terminal segment of the tail, the rectangular lateral termination of the segments of the body, and the curious character (to which he has first directed our attention) that each of the false feet, or branchial plates of the tail, are marked with small white spots at the base ; whereas in the other species it is only in the first and second pairs of those organs that this character is to be found. These characters do not appear to us, however, to be of suffi- cient importance to warrant the establishment of a new genus for the P. Icevis. Its colour is of a leaden grey, occasionally blotched with yellow on the sides. It is sluggish in its habits, and occurs commonly in stable-litter, and among grass at the bottom of walls. It occurs in England and Ireland. Kent, and the neighbourhood of London and Dublin, have been re- corded as the localities. PORCELLIO ARMAD1LLOIDES. ISOPODA. NORM All A. 485 ONI SCI DM. PORCELLIO ARMADILLOIDES. Specific character. Elongate-elliptical. Segments very convex and smooth. Lateral lobes of the front of the cephalon minute, obliquely truncated in front. Central lobe very short, angular, and acute. Terminal segment of the pleon acute, flat above, or slightly convex. Length, half an inch. Porcellio armadillo ides. LEREBOULLET, Mem. Soc. Nat. Hist. Strasbourg, iv. 1853. KINAIIAN, Dublin Nat. Hist. Rev. iv. 1857, p. 279. DE GEER, Mem. Ins. vii. p. 553, pi. 35, f. 11. JOHNSSON, Syn. Frams. Sver. Onisc. p. 32. HARTMANN. Oniscus convexus. Oniscus saxatilis. THIS species is well distinguished by its narrow and almost cylindrical form, reminding the observer strongly of the species of the genus Armadillo. The lobes of the head are but slightly developed, the lateral ones having a 486 ONISCID^E. rounded margin and a concave upper surface. The seg- ments of the body have the posterior angles acute. The third, fourth, and fifth segments of the tail are largely developed, their lateral margins being continuous with that of the sides of the body-segments. The terminal segment of the tail is elongate-conic, and pointed at the tip, with the upper surface slightly convex, and extending to about one-third of the length of the outer division of the terminal appendages of the tail, which are elongate, slender, and pointed at the tip. The general colour is iron-grey, with clear borders to the segments, and with a row of ill-defined whitish spots on each side of the body, parallel with the lateral margins. When alive, it rolls itself into a perfect ball on being alarmed. Specimens taken near London (at Highgate ?) by Mr. Francis Walker, are in the cabinet of the British Museum. ISOPODA. NORM All A. PORCELLIO PRU1NOSUS. 487 ON/SCIDJZ. PORCELLIO PRU1NOSUS. Specific character. Subovate, oblong, slightly rugose, and downy. Lateral lobes of the front of the cephalon small and rounded. Central lobe minute, almost linear. Pleon narrow, with the terminal segment triangular, acute at the apex. Pereiopoda long. Length, about one-third of an inch. Porcellio pruinostis. BRANDT, Conspectus Mon. Onisc. Bull. Mosc. vi. p. 181. KINAHAN, Dublin Nat. Hist. Rev. vol. iv. 1857, p. 278, pi. 19, figs. 3, 5, 7, pi. xxi. fig. 1. Porcellio frontalis. LERBBOULLET, Mem. Soc. Hist. Nat. Strasbourg, iv. 1853 (not of MILNE EDWARDS). JOHNSSON, Syn. Framst. Sver. Onisc. p. 30. (Var.?) P.maculicornis. KOCH, Cont. Panz. Heft. 180, n. 16. BUKGERSDIJK, Annot. p. 48. THIS species, although one of the commonest of our British wood-lice, was first detected by the late Professor 488 ONISCIOE. Kinahan, having been confounded with P. scaber, from which, however, it is at once distinguished by its more elongate form, less rugose surface, and especially by the narrowness of the tail, in which respect it approaches the species of the genus Philoscia. The posterior angles of the three anterior joints of the body are obtuse, and those of the following joints are much less acutely pro- duced backwards than in most of the other species of the genus. The lobes of the head are but slightly pro- duced, the central one being small and rounded. The tail is small, the three principal segments being com- paratively minute, as compared to their size, in the preceding species. The terminal joint is short and triangular, its extremity only extending a little beyond the base of the terminal division of the apical appen- dages of the tail, which is considerably elongated, as are also the legs ; the whole structure of the animal indi- cating greater activity and powers of movement. The variety P. maculicornis of Koch is of an iron colour, with the outer antennae ringed with white, the segments of the body having the posterior margins simply granulated, and the terminal appendages of the tail of a ferruginous colour. The species is of an uniform mouse-grey colour, seen under a lens to be marked with white. It generally con- ceals itself rapidly from the light, but, when disturbed, runs with great rapidity. It prefers moderately humid warm situations, and occasionally buries itself in the earth, even in clayey localities, to a considerable depth. It is very common both in England and Ireland. The neighbourhoods of Dublin and Chiselhurst, Kent, are localities in which they are found. It is equally plen- tiful in the vicinity of Oxford. PORCELLIO CINGENDUS. ISOPODA. NORMAL1A. 489 ONISCIDJE. PORCELLIO CINGENDUS. Specific character. Elongate-ovate, smooth or but slightly scabrous, glossy. Lateral lobes of the front margin of the cephalon minute and deflexed ; the median one nearly obsolete. Terminal segment of the pleon broadly trian- gular, flat above, with the apex acute. Length, nearly one-third of an inch. Porcellio cingendus. KINAHAN, Dublin Nat. Hist. Rev. vol. iv. 1857, p. 279, pi. xix. figs. 1, 2, 4, 6, 8, and 9. THE minute development of the lateral and frontal lobes of the anterior margin of the head, the narrowness of the segments of the tail, and the broadly triangular terminal segment of that part of the animal, well dis- tinguish this species from most of its congeners ; whilst the smooth shining body, and the rounded postero-lateral angles of the segments of the body, serve to separate it 490 ONISCID^. from P. pruinosus, in company with which it is often found, and of whicli it might be mistaken for the young, which latter, however, do not differ from their parents. The basal portion of each of the segments of the body is marked with a transverse raised line, whence the name given by Professor Kinahan to the species. It is of a dark steel colour, with red and yellow spots. It runs with very great rapidity, and never rolls itself into a ball, as might indeed be surmised from the small develop- ment of the lobes of the head, which form, in other species, the defence of the antennas when at rest. It is very rare. Specimens taken near Dublin by Professor Kinahan, are in the collection of the British Museum and our own cabinet. ARMADILLO. 49] ISOPODA. ONISCIDJ?. XI0RMAL1A. Genus— ARMADILLO. (Latreille.) * ARMADILLIDIUM. (Brandt.) Generic character. Elliptical, very convex. Outer antennae seven-jointed. Coxae of the first and sixth segments of the pleon obsolete. Uropoda with the basal portion flattened, trun- cate ; terminal portion broader than long, not extending beyond the extremity of the pleon, with which its apical margin forms a continuous line : accessory filament flattened, club-shaped, concealed. This genus forms a distinct section of the family on account of the structure of the last pair of the appen- dages of the tail, which do not extend beyond the extremity of that part of the body, their truncated extremity forming a continuous line with the lateral margin of the fifth segment of the tail, and the extremity of the sixth joint. " The eyes are supported on the cephalic segment alone. The margin of this is raised, forming an angular projection in the middle of the forehead, passing back from whence, as it forms the orbital margin, to the entire exclusion of the third segment, the lateral lobes being here remarkably small, and derived entirely from the cephalic segment." — Kinahan. The animals, when alarmed, have the habit of rolling their bodies into a perfect globular mass, the antennae being completely concealed, for which purpose the front margin of the head is provided with a groove on each side, within which the basal joints of the outer pair of these organs are lodged (fig. a). * The Mammalians thus popularly named being generically known under the name of Dasypus, we have retained Latreille's name of Armadillo, which has been generally adopted for these Crustaceans. 493 ONISCIDiE. ISO POD A. NOR MA LI A. ONISCIDJ?. ARMADILLO VULGARIS. Specific character. Elliptical, very convex, upper surface delicately punc- tured ; of a dark leaden or steel-grey colour, with paler spots, and with the hind margins of the segments generally pale. Second joint of outer an- tennae with the tip dilated at its outside. Uropoda with the outer division broad, short, exactly filling the space between the sides of the terminal and penultimate segments of the pleon. Length, about half to two-thirds of an inch. Oniscus armadillo. A rmadillo vulgaris. Linnaeus, Syst. Nat. ii. p. 1062. Latreille, Hist. Nat. Crust, et Ins. vii. p. 48. Genera Crust, et Ins. i. p. 70. Leach, Edinb. Encycl. vii. p. 406. Trans. Linn. Soc. xi. p. 376. Suppl. Enc. Brit. i. p. 429. Samouelle, Ent. Compend. p. 112. Desmarest, Cons. Crust, p. 325. White, Cat. Brit. Crust. p. 73. Pop. Hist. Brit. Crust, p. 238. ARMADILLO VULGARIS. 493 A rmadillidmm vxdqarc. Armadillium vulgare. Oniscus cinereus. (Var.) Armadillo variegatus. A rmadillidium Zenkeri. (Var.) Armadillo opacvs. (Var.) Armadillo Willii. A rmadillo pulchellm. Milne Edwards, Crust, iii. p. 184. Bur- gersdijk, Annot. p. 51. Zaddacii, Syn. Crust. Pruss. p. 19. Johnsson, Syn. Framst. Sver. Onisc. p. 34. Kinahan, Nat. Hist. Rev. vol. iv. 1857, p. 276, pi. xxi. figs. 3, 9—13. Zenker, in Panzer, Heft. 62. n. 22. Latreille, Gen. Cr. et Ins. i. p. 72, n. 2. Koch, Cont. Panzer, Heft. 178 n. 15, and 186, n. 2. Brandt, Consp. Mon. Crust. Onisc. Bull, Mosc. vi. 185. Koch, Cont. Panz. Heft. 180, n. 3. Koch, Cont. Panz. Heft. 186, n. 1. Schnitzler, Onisc. Bonn. p. 26 (?). This very widely dispersed species is subject to great variation in the amount of its pale markings, which has led to the establishment of a great number of supposed species, as appears from the citations quoted above. We have not been able to recognize more than a single species amongst them, which is well distinguished by the perfectly globular form in which it is able to roll itself up when alarmed, as represented in the lower left-hand figure of the accompanying wood-cut. The extremity of the tail and of the flattened truncated appendages of the last caudal segment exactly coincides with the front margin of the head, completely concealing the deflexed antennae and legs. The head is produced on each side immediately below the eye into a short transverse ridge, forming the upper edge of a groove, within which the basal joints of the antennas are lodged; the lower edge of the groove being also produced into a moderately prominent rounded lobe. The labrum or upper lip is triangular, and transversely prominent along its straight upper edge. The inner antennae are very minute and apparently three-jointed, the middle joint being the smallest, but 494 0NISC1D.E. under a strong magnifying power the rudiments of two very minute terminal joints are to be perceived, as well as several short thickish spines. The large outer antennae are seven-jointed, the second joint roundly dilated at its outer edge at the tip, the fifth joint long, the seventh the slenderest, with a minute distinct seta at the tip. The third segment of the tail is laterally continuous with the edge of the seventh segment of the body, the two basal segments of the former, although quite dis- tinct, being short and greatly abbreviated at the sides. The hind margin of the fifth segment is semicircular, the emargination being filled in by the small triangular sixth segment, of which the apex is obtuse, and by the flattened and truncated outer division of the first pair of false legs, the inner division being small, flattened, and ovate. The five anterior pairs of appendages of the tail differ considerably in form, the first pair being composed of two flattened, somewhat triangular, plates ; the second pair in the male is nearly similar in form, but is provided with a large pair of elongated horny lobes, slightly curved at the tips ; the third pair in the male is more sabre-shaped, with a slender horny appendage, having the tip bent and acute ; the fourth, fifth, and sixth pairs have the plates triangular-shaped. The general colour is leaden, or dark steel-grey, with spots and patches of dull buff or whitish : it varies, however, to brownish testaceous. It inhabits rather dry places under stones, decaying timber, and among herbage, and is often seen running about foot-paths, rolling itself up into a ball at the least alarm. This has gained for it the name of Pill millepede, and in " former times it was highly reputed for its supposed medicinal virtues, the old books of Materia Medica informing us that when dried and pulverized they have a faint disagreeable ARMADILLO VULGARIS. 495 smell, and a somewhat pungent, sweetish, nauseous taste, and are highly celebrated in suppressions, in all kinds of obstructions of the bowels, in the jaundice, ague, weak- ness of sight, and a variety of other disorders." And the wine of Millepedes, prepared by crushing these animals when fresh, and infusing them in Rhenish wine, is spoken of as an " admirable clearer of all the viscera, yielding to nothing in the jaundice and obstructions of the kidneys. In the light of modern science, we can impute the cures attributed to these creatures only to the effect produced upon the imagination of the patient, and the curative powers of nature, for, beyond some slight demulcient qualities, they must be wholly inert, and are now wisely discarded from the Pharmacopseias." (Fitch, in Report on Noxious, Beneficial, and other Insects of the State of New York. Albany, 1855.) They are still taken medi- cinally in some parts of Somersetshire. The species is very widely dispersed and very common. Its recorded localities are near London, and in Kent, and generally throughout Ireland. It is very abundant in the Midland counties, as well as in Devonshire and Cornwall. APPENDIX. DESCRIPTIONS OF NEW SPECIES. AMPIIIPODA. SALTATORIA. ORCHESTIIDjE. ( Vol. I. p. 37.*) ORCHESTIA. BREVLDIGITATA, N.S. Specific character. Second pair of gnathopoda with the propodos broader at the distal extremity ; the palm being at right angles with the upper margin, nearly straight, fringed with a series of equidistant setae, and bounded below by an obtusely rounded lobe. Length, about eight- twentieths of an inch. This species differs from any that we have hitherto examined. It bears a closer resemblance to 0. euchore, which Dr. Fritz Miiller has described, from the shores of Brazil, than any- other with which we are acquainted. The most striking feature is that of the form of the second pair of gnathopoda, as described above. The dactylos of the second pair of gnathopoda is nearly one-third shorter than the palm, and one-half the width of VOL. II. K K 498 APPENDIX. the distal margin of the propodos. In 0. euchore the hand is more ovate, and the dactylos reaches to the extremity of the palm. The hand of the second pair of gnathopoda is smaller in proportion than that of the male in other species, which, together with the size of the animal, incline us to believe the specimen to be a not yet fully grown animal. We are indebted for this species to Mr. Edward, who took it near Banff. Its eyes are black, and its colour a light olive-green. It probably has been passed over for the young of the more common species. APPENDIX. 499 A MP HI POD A . STEGOCEPHA LIDES. NATATORTA. (Vol. I. p. 66*.) MONTAGUA CLYPEATA. Specific character. Second pair of gnathopoda with the propodos oblong, slightly widening to the distal extremity, where it is truncated, terminating below in a porrected point ; the palm slightly curved and serrated. Length, three -twentieths of an inch. Montagua clypeata. Spence Bate, Cat. Amph. B. M. p. 58, pi. ix. fig. 4 Leucothoe clypeata. Kroy., Nat. Tids. iv. p. 141, pi. 6, fig. 2a. Lilljeborg, in Ofvers. af Kongl. Vetensk. Forhandl. , 1851. Some specimens, taken by the Eev. A. M. Norman off the coast of Northumberland, agree so closely with the description and figures of Kroyer above referred to, that we have little doubt but that they belong to the species which he has de- scribed under the above name. The form of the hand of the second pair of gnathopoda, of which we give a figure, bears such a relation to that which we have described as belonging to M. iwllexiana, that we are inclined to believe that Kroyer's specimen may be but the female of ours. But this is yet to be determined, in which case our species would yield its name to the earlier one of Kroyer. K K 2 500 AMPHIPODA. NATATORIA. APPENDIX. STEGOCEPHA LTDES. Vol. I. p. 66.* MOiNTAGUA NORVEGICA. Specific character. Second pair of gnathopoda having the propodos large and oblong, armed in the middle of its under edge with a strong projecting tooth, reaching as far as the under angle of the serrated palm. Length, about a quarter of an inch. Montagua norvegica. Sp. Bate, Cat. Amph. B. M. p. 370. Leucothoe norvegica. Lilljeborg, Ofvers. af Kongl.Vet. Akad. 1850, p. 335. Bruzelius, Skand. Amph. Gam. p. 97. This species appears to agree with Lilljeborg's description of Leucothoe norvegica, chiefly in the formation of the propodos of the second pair of gnathopoda. The hand is large, and armed with a strong sharp tooth that projects from near the middle of the lower or posterior margin, the apex of which reaches to a line with the palm, from which it is separated by a deep excavation, the anterior margin of which is directed in a line parallel with the anterior margin of the propodos. The palm is straight, furnished with five small broadly based denticles. The dactylos reaches beyond the palm, but does not extend to the extremity of the thumb-like tooth of the hand. This species was taken near Banff by Mr. Edward. APPKNDIX. AMPH1P0DA. NATAT0R1A. 501 LYSIANASSIDES. {Vol. I. p. 118.*) Genus — OP1S. (Kroyer.) Generic character. Resembles Anonyx, with the exception tbat the first pair of gnathopoda have the inferior angle of the propodos considerably produced, so that the hand is formed into a didactyle chela. OPIS LEPTGCHELA, N.S. Specific character. Upper antenna? with the two basal joints large ; lower antennse half as long again as the upper. Both pairs of gnathopoda minute, slender, and subequal. Length, about one-fourth of an inch. The cephalon is small, not produced anteriorly. The segments of the pereion and pleon are dorsally subequal in length ; the fourth segment of the pleon having a deep notch on the dorsal surface. The eyes are small and round. The first two joints of the superior antennse large ; the flagellum short; secondary appendage short. The inferior antennse are slender, being half as long again as the superior. Coxae deep. Gnatho* 50.2 APPENDIX. poda slender, cylindrical, subequal ; first pair having the propodos nearly as long as the carpus ; inferior angle longi- tudinally produced to a fine point, slightly curved ; dactylos as long as and parallel with the digital process of the pro- podos : second pair rather more slender than the first, with the propodos nearly as long as the carpus, and furnished with a copious brush of hairs ; dactylos minute, simple, almost lost in the cilia of the preceding joint. Periopoda short and robust. Specimens of this species have been taken by the British Association Dredging Committee in the Shetlands, and by Mr. G. Brady, on a specimen of Echinus esculentus, off the Isle of Man. AMPHIPODA. NATATORIA. APPENDIX. 503 LYSIANASSIDES. ( Vol. I. p. 118.**) OPTS QUADRIMANA, N.S. Specific character. Upper antennae with the secondary appendage nearly reaching to the extremity of the flagellum. First pair of gnathopoda with the propodos quadrate, truncated at the end, the inferior angle armed with a strong pointed spine. Length, one-eighth of an inch. This species differs from the preceding in having the superior antennae longer, and furnished with a secondary appendage that reaches nearly to the extremity of the flagel- lum ; the inferior antennae being scarcely longer than the superior, and in the first pair of gnathopoda being much more robust than the second. The propodos of the first pair is quadrate, the palm being at right angles with the anterior and posterior margins, and armed with a minutely denticu- lated thickened margin ; inferior angle produced to a short strong tooth, against which the apex of the slightly curved dactylos impinges. This species was sent to us by Mr. Edward, who took it off the Banffshire coast. 504 AMPHIPODA. XATATORTA. APPENDIX. AMPEL1SCIDES. Vol. I. p. 137.") AMPELISCA LAEVIGATA. Specific character. Posterior margin of third segment of pleon regular. Superior antennae attached to the lower angle of the anterior margin of the cephalon. Length, about one-fifth of an inch. Ampelisca, laevigata. Lilljeborg, Ofvers. af Kongl. Vet. Akad. Forhandl. Spence Bate, Cat. Amph. B. M. p. 96. We have received from the Eev. A. M. Norman a specimen that probably belongs to this species. It differs little from A. belliana, except in the absence of the ornate character of the posterior margin of the third segment of the pleon, and in having the superior antennas attached to the lower angle of the anterior margin of the cephalon. It was taken off the coast of Durham. Lilljeborg obtained his specimen at Kullaberg, on the coast of Norway. APPENDIX. AMPHIPODA. NATATORIA. 505 AMPEL7SCIDES. (Vol. Lp. 137/*) Genus— HAPLOOPS. {Lilljeborg.) Generic character. Closely allied to Ampelisca, but differs in having the cephalon less anteriorly produced, and the organs of vision reduced to two. HAPLOOPS TUBICOLA. Specific character. Superior antennae about one-third of the length of the animal, ciliated beneath, without an accessory filament. Two pairs of gnatho- poda small and hairy. First and second pereiopoda terminated by long stylate fingers. Length, about half an inch. Haploops tulicola. Lilljeborg, Ofvers. af Kongl. Vet. Akad. 1855. Bruzelius, Skand. Amph. Gam. p. 88. Spence Bate, Cat. Amph. B. M. p. 371. Ampelisca Esclirichtiil Lilljeborg, 1. c. 1852, p. 6. Cephalon anteriorly depressed, without a rostrum, having the superior antennae affixed to the apex, about one-third the length of the animal, and inferiorly ciliated ; inferior antennae slightly longer than the superior : gnathopoda subequal, hairy : first two pairs of pereiopoda with long stylate dactyla, 506 APPENDIX. third and fourth pair having the basis round, and the dactylos short, curved, and posteriorly directed ; fifth pair having the basis long and narrow, and the propodos and dactylos almost rudimentary : posterior pair of pleopoda long, with two sub- equal rami, ciliated, on the inferior margin ; telson two-lobed. This species was first taken off the coast of Norway, in 1S54. It has since been taken in England, off Tynemouth, off the Holy Island, and in the Shetlands, by the Rev. A. M. Norman. APPENDIX. AMPIIIPODA. NAT ATOM A. r>07 PHOXIDES. [Vol. I. p. 170.*) MONOCULODES LONGIMANUS, N.S. Specific character. Dorsal surface slightly carinated. gnathopoda long and narrow, resembling the second pair. Length, about one -fifth of an inch. First pair of This species differs from those previously described in having the first pair of gnathopoda long and narrow, and in fact developed more nearly on the type of the second pair. The dorsal surface is slightly carinated. It was sent to us from Banff by Mr. Edward. We have two specimens, both of which have the superior antennae wanting, while in one the inferior antennae are short, and in the other they are long and slender. We consider the latter to be the male form, and the former the female. 508 AMP HIP OD A, NAT A TORI A. APPENDIX. PHOXIDES. {Vol. I. p. 178.*) KROYERA BREVICARPA, N.S. Specific character. Superior antennre short ; inferior as long as the entire animal. Second pair of gnathopoda chelate, with the lower angle of the carpus not extending along the inferior margin of the propodos. Length, ahout one-sixth of an inch. This species differs from those previously described in having the superior antennae short and thickly furnished with auditory cilia; the inferior antennae being as long as the animal ; the first pair of gnathopoda, with the propodos, ovate, having the palm armed with three or four obtuse denticles and two rows of hairs, and defined by a strong spine ; the anteriorly produced carpus also terminating in a strong spine ; and in having the second pair of gnathopoda chelate, with the antero-inferiorly produced angle not extended along the inferior margin of the propodos. It was taken at Banff by Mr. Edward. APPENDIX. 509 A MP HIP OD A. NATATORTA. LYSIANASSIDES. (Vol. T. p. 118.***) Genus— LEPIDEPECREUM. Generic character. Cepkalon having the orbital or intra-anten- nal process considerably developed and produced. Pereion well developed. Pleon having the last four segments very short. Eyes not made out; supposed to occupy the intra-antennal process; — superior antennae having the upper surface of the first two joints of the peduncle considerably produced anteriorly, having no secondary appendage. Inferior antennas posterior to the superior. Mandibles furnished with a Particulate appendage. First pair of gnathopoda moderately robust, subchelate. Second pair feeble and chelate or subchelate. Posterior pair of pleopoda short, biramous. Telson — ? LEPIDEPECREUM CARINATUM, N.S. Specific character. Body dorsally carinated. Segments subequal. Fourth and fifth segments of pleon produced into a tooth. Gnathopoda minute and slender. Length, one-fifth of an inch. The cephalon has the intra-antennal process produced anteriorly as far as the infero-distal extremity of the first joint 510 APPENDIX. of the peduncle of the superior antennas, when the latter is deflected in the same line. The segments of the pereion and the anterior three of the pleon are subequal ; the three posterior segments of the pleon very short; and the fourth and fifth dorsally produced into a tooth. The superior antennae have the first joint of the peduncle thick, and as long as the cephalon, with the upper surface anteriorly produced into a scale-like process, quite as far as, if not beyond, the distal extremity of the third joint of the peduncle ; second joint with the upper surface anteriorly produced like the first ; third not so produced ; flagellum short, consisting of four or five articuli. The inferior antennas are short, having the peduncle longer than the flagellum ; flagellum consisting of four articuli ; and the whole organ not reaching beyond the extremity of the first joint of the peduncle of the upper antennae. The first pair of gnatho- poda have the propodos but little longer and not broader than the carpus ; anterior and posterior margins subparallel ; palm slightly oblique, and defined by an acute tooth ; dactylos short and curved. The second pair of gnathopoda have the propodos shorter than the carpus, anterior and posterior margins curved, sub-parallel ; digital process short and conical ; dactylos not longer than the digital process of the propodos, conical, curved. The pereiopoda are short, robust, subequal last pair slightly the longest ; third pair having the coxa quadrate, half as deep as that of the preceding ; basos circular, as deep as the coxa ; meros posteriorly produced to a thin angular plate. The fourth and fifth pairs differ from the third in being less robust and slightly longer. The rami of the three posterior pairs of pleopoda short. The telson has not been made out. Taken at Banff by Mr. Edward, associated with Anonyx longicomis, with which it is very closely allied, being perhaps a young female. Anonyx longioornis (vol. i. p. 91).— The absence of a secon- dary appendage to the upper antennae must separate it from the genus Anonyx, to which it is assigned in the body of the work. We therefore arrange it in the present genus in consequence of its near affinity with the last species. APPENDTX. 511 AMPHIPODA. N ATA TORI A. GAMMARIDES. ( Voh I. p. 259.) Genus— NICiPPE. (Bruzdius.) Nicippe. Bruzelids, Skan. Amph. Gam. p. 99. Spence Bate, Cat. Aniph. B. M. p. 373. Generic character. Animal generally robust. Segments of the pereion subequal, the three anterior of the pleon slightly longer, increasing posteriorly. Cephalon nearly as long as the first two seg- ments of the pereion. Superior antennae longer than the inferior, and furnished with a small secondary appendage. Coxa moderate, suhequally deep. Gnathopoda subequal, subchelate. Two posterior pairs of periopoda considerably longer than the preceding. Posterior pair of pleopoda biramose. Telson simple; deeply cleft. NICIPPE TUMID A. Specific character. Superior antennas nearly half the length of the body, with a small three- jointed secondary appendage. Upper antennas rather shorter. Gnathopoda subequal, with the propodos elongate-ovate. Three posterior pairs of pereiopoda gradually elongated. Length, half an inch. Nicippe tumida. Bruzelius, Skand. Amph. Gam. p. 99, fig, 19. Spence Bate, Cat. Amph. B. M. p. 374. Fourth segment of the pleon having the posterior margin furnished with two small lateral teeth on the dorsal surface. 512 APPENDIX. Eyes not recognizable in specimens that have reached us. Superior antennae longer than the inferior, having a small tri- articulate secondary appendage ; inferior antennae having the peduncle longer than the peduncle of the superior. Gnatho- poda subequal and similar, having the inferior margin and palm furnished with long cilia. Dactylos long and slender. First two pairs of pereiopoda subequal and of moderate length ; third pair not longer than the preceding ; fourth pair about one third as long again; fifth pair longer than the fourth ; posterior pair of the pleopoda subfoliaceous and ciliated. Telson single, but cleft deeply, so as to appear double. We have received one or two specimens from Mr. Jeffreys, who dredged them off the Shetlands. APPENDIX. AMPUIPODA. NAT A TORI A. 513 GAMMARIBES. {Vol. I. p. 347*) Genus— CHEIROCEATUS. {Norman.) Trans. Nat. Hist. Soc. Northumberland and Durham, vol. i. p. 12. Generic character. Long and slender. Segments of the pereion and pleon subequal. Eyes round. Antennae subequal ; peduncle of the superior shorter than the peduncle of the inferior; furnished with a secondary appendage. Mandibles having a long appendage. Gnathopoda unequal : first pair simple ; second pair long, large, and robust. Posterior pair of pereiopoda longer than the preceding. Posterior pair of pleopoda long and unibranched. Telson double. C1IEIROCRATUS MANTIS. Specific character. Dorsal surface of the fourth segment of the pleon produced posteriorly into a short central and a long lateral tooth on each side, the space between being occupied by a long cilium. Fifth segment resembling the fourth, but having the teeth less important and the cilium absent. Length, nearly half an inch. Cheirocratus mantis. Norman, op. cit. vol. i. p. 13, pi. vii. figs. 14, 15. The superior antennae about the length of the cephalon VOL. II. L L 514 APPENDIX. and the four anterior segments of the pereion. Flagellum about the same length as the peduncle. Secondary appendage small. The inferior antennae are a little longer than the supe- rior, the peduncle being about three-fourths of the antennae. The first pair of gnathopoda are cylindrical, having the poste- rior margin of the carpus and propodos thickly ciliated ; carpus as long as the propodos, tapering ; dactylos apical, straight. The second pair of gnathopoda are long ; propodos ovate; palm oblique, denned by a strong tooth, armed near the base of the dactylos with a double dentated tubercle, and near the middle with three teeth, of which the anterior is the largest; dactylos short, shorter than the palm, curved and simple. The three posterior pairs of pereiopoda have the basos narrow and the entire appendage increasing posteriorly in length ; the posterior pair of pleopoda having the ramus nearly three times as long as the peduncle. The telson is tipped with strong cilia. This species was first taken and described by the Rev. A. M. Norman, from a single specimen dredged in deep water off Holy Island. We have since received it, through Mr. Dawson, from the coast of Aberdeenshire. APPENDIX. AMPIHPODA. NAT ATOM A. 515 OAMMARIDES. ( Vol. I. p. 410.*) MEGAMCERA MULTIDENTATA. (Norman M88.) Specific character. Body long and slender. Second segment of pleon with three teeth on the middle of the posterior margin ; third segment with four ; fourth, fifth, and sixth segments with two similar teeth, Length, six-tenths of an inch. The body is long and slender, with the segments subequal ; the second segment of the pleon having a central, and on each side a lateral tooth on the posterior dorsal margin ; third having a central and two lateral teeth on the dorsal margin ; the three following segments without a central, but possessing on each a lateral tooth, at the base of which a strong hair or spine exists. The eyes are round and black. The superior antennae are half the length of the animal, and the peduncle is half the length of the antennae. The first joint is as long as the cephalon ; the second joint is a little longer and slighter than the first; the third is short. The articuli of the flagellum are as long again as broad ; the secondary appendage consists of five articuli. The inferior antennae are about half the length of the superior ; the peduncle extends to the extremity of the second joint of the peduncle of the superior. Olfactory denticle L L 2 516 APPENDIX. long and prominent. Third joint of the peduncle short and stout, and furnished at the infero-anterior angle with a strong tooth and a few hairs. Fourth and fifth joints long, slender, and subequal. The flagellum consists of eight articuli. First pair of gnathopoda slender; propodos shorter and not broader than the carpus, furnished with numerous and long hairs ; dactylos short and impinging closely on the palm. Second pair long and well developed ; carpus distally dilated : pro- podos subconfluent with the carpus, long, broad ; inferior and superior margins subparallel ; palm oblique, armed near the centre with a broad flat-headed tubercle, furnished with a few hairs, slightly posterior to which is a double-cusped process, or strong tooth, between the two points of which the apex of the dactylos impinges ; and at the infero-anterior angle are two prominences, carrying one or two strong straight spines : the dactylos is very robust, abruptly curved, sharp at the point, and shorter than the palm. Posterior pair of pleopoda (want- ing). Telson double-lobed ; each lobe surmounted by a single spine. Hah. — Guernsey, where it was taken by the Rev. A. M. Norman. APPENDIX. 517 A MP HIP 0 DA, DOMICOLA. PODOCERIDES. {Vol. I.p 491.*) Genus— UNCIOLA. Unciola. Say, Journal Acad. Nat. Sci. Philad. i. p. 389. Edwards, Ann. des Sc. Nat. t. xx. p. 383. Hist, des Crust, iii. p. 69. Glauconome. Kroyer, Nat. Tidsk. i. p. 501. Spence Bate, Cat. Amph. B. M. p. 278. Generic character. Long and slender, not much compressed. Segments subequally long, increasing in length a little posteriorly to the third segment of the pleon. Eyes small and round. Superior antennse furnished with a slender flagellum and a small secondary appendage. Inferior antennae subequal with the superior. Gnatho- poda robust : first pair subchelate ; second pair not subchelate. Pereiopoda long and slender ; coxae small, subequal ; basos of the three posterior pairs but slightly, if at all, enlarged. Posterior pair of pleopoda having but a single branch, and that almost rudimentary. Telson single, flat. 518 APPENDIX. UNCIOLA LEUCOPE?*. Specific character. Upper antennae nearly half the length of the animal. Secondary appendage minute. G-nathopoda fasciculated. Terminal pleopoda armed with short strong spines. Length, one-third of an inch. Unciola hucopes. Kroyer, Nat. Tidsk. i. 491, pi. 7, fig. 2. Spence Bate, Cat. Amph. B. M. p. 279. ,, planipes. Norman, Trans. Nat. Hist. Soc. of Northumberland and Durham, vol. i. pi. vii. figs. 9 — 13. The eyes are small. The antennae are subequal, the superior pair nearly half the length of the animal: first joint of the peduncle rather longer than the cephalon ; second rather longer than the first ; the secondary appendage being small. The inferior antenna} are shorter than the superior, having the peduncle rather longer than the peduncle of the superior. The gnathopoda are armed with fasciculi of hairs ; first pair having the propodos ovate, with the palm waved and imper- fectly denned, furnished with several fasciculi of long cilia ; dactylos serrated along the inner margin. Second pair having the carpus almost as long again as the propodos ; propodos tapering; dactylos apical, minute. The pereiopoda are long, slender, and cylindrical. The pleopoda have the antepenultimate pair longer than the penultimate ; the penultimate longer than the ultimate ; ultimate scarcely reaching beyond the telson. Telson circular. This species was taken by the Rev. Mr. Norman off Holy Island, on the coast of Northumberland and Durham, and named by him U. planipes in the Transactions of the Natural History Society of Northumberland and Durham. We had previously received it from the Haaf Ground, Shetland. We believe, however, that the species probably is identical with Kroyer's Greenland species, the distinction between the two arising from omissions in description and figure rather than any clear variation of character. APPENDIX. AMPHIPODA. HYPERINA. 519 HYPEMIDM. ( Vol. II. p. 18.*) HYPERIA TAURIFORMIS, N.S. Specific character. Antennae very short. Both pairs of gnathopoda with the proximate margins of the propodos and carpus strongly serrated, as well as the dactylos of the second pair. Length, four-twentieths of an inch. The antennas in this species are very short. The inferior angle of the carpus is anteriorly produced in both pairs of gnathopoda, and the proximal margins of the propodos and carpus are strongly serrated, as also is the dactylos of the second pair. Dana established the genus Tauria for the reception of those species of Hyperia that have the anteroinferior angle of the carpus of both pairs of gnathopoda so far anteriorly produced as to extend to the extremity of the propodos, thus forming a tolerably perfect but compound chelate organ. But so gradual is the development of this process from one species to another, that we can see no clearly denned limit where one genus may commence and the other end. We have chosen a specific name for our new species which indicates its affinity with Dana's proposed genus. The animal above described was taken at Banff by Mr. Edward. 520 AMPHIPODA. HYP ERIN A. APPENDIX, HYPERIDAi. ( Vol. II p. 18.**) HYPEUIA PREHENSILIS, N.S. Specific character. Superior antennas about the length of the Lead. Both pairs of gnathopoda with the carpus and rjropodos simple. Three hind pairs of pereiopoda subprehensile at the tips. Length, three-twentieths of an inch. This species differs from H. tauriformis next described in having longer antennas, the proximal margins of the carpus and propodos of both pairs of gnathopoda not serrated, and in having the propodos of the last three pairs of pereiopoda interiorly produced and armed with short strong cilia. This gives a prehensile character to the last three pairs of pereio- poda that we have not recognized in other species. Taken at Banff, by Mr. Edward, with the preceding species. APPENDIX. 521 A MPI1IP0DA . // YPERIIBjE. HYPERINA. ( Vol. II. p. 18.***) HYPERIA CYANEJE. Specific character. Superior antenna? very short ; flagellum scarcely longer than the peduncle. Gnathopoda subequal and nearly alike ; first pair short, with the propodos subovate ; superior margin arcuate, inferior straight. Dac- tyla of thi*ee posterior pairs of pereiopoda long, sharp, and furnished with a bunch of cilia in the middle. Length, rather more than three -twentieths of an inch. Talitrus cyanea. Sabine, Appendix to Parry's Voyage, pi. i. figs. 12 — 18. Metoechus cyanece, Edwards, Hist, des Crust, iii. p. 78. White, Cat. Brit. Crust. (Brit. Mus.) 1847. Hyperia cyanece. Spence Bate, Cat. Amph. p. 294, pi. 48, fig. 10. A specimen of Hyperia has been sent to us by Mr. Edward, of Banff, that we take to be a variety of this species: it differs in having the antennae much less developed than those in the typical specimens. It looks like a young H. Galba, with rudimentary antennae, but one of the specimens sent to us has the incubatory pouch of the adult female fully developed, so that we cannot mistake it for a young animal. Mr. Edward says that he has never taken this species in a Medusa, and that he has frequently found it on the shores of the Moray Frith in December, January, and February, that is, at a time when the Medusae are not on the coast. 522 APPENDIX. AMPHIPODA. HYP ERIN A. HYPERIIDjE. {Vol. II. p. 18.****) Genus— THEMISTO. (Guerin.) Themisto. Gttkrin Meneville, Mem. de la Soc. d'Hist. Nat. de Paris, iv. 1828. Edwards, Ann. des Sci. Nat. xx. p. 393. Hist, des Crust, iii. p. 84. Spence Bate, Cat. Amph. Brit. Mus. p. 311. Generic character. Cephalon transversely ovate. Perion not dis- tended. Pleon slender. Eyes occupying the entire cephalon, dor- sally separated. Antenna? short ; superior pair having the flagellum cylindrical and uniarticulate ; inferior pair more slender, and having the flagellum multiarticulate. Mandibular having an appendage. First pair of gnathopoda short, with the inferior angle of the carpus not anteriorly produced ; second pair having the inferior angle of the carpus anteriorly produced. First two pairs of the pereiopoda having the carpus dilated, the propodos cylindrical, and the dactylos inflected back against the carpus. Third pair of pereiopoda extremely long, being twice the length of the preceding pair, and armed anteriorly with a series of comb-like seta?. The last two pairs of i>ereiopoda not half the length of the preceding. Three poste- rior pairs of pleopoda being long. Telson single. APPENDIX. 523 L THEMISTO CRASSICORNIS. Specific diameter. Superior antennre very short, thick, biarticulate, fur- nished along their under surface with numerous auditory cilia; inferior antenna with a flagellum composed of one short and one long joint. First two pairs of pereiopoda having the carpi subovate, smooth, and unarmed along the inferior margin. Length, half an inch. Themisto cnissicornis. Kroyer, Gronl. Amfip. p. 67, pi. iv. fig. 17. Edwards, Hist, des Crust, t. iii. p. 85. Spence Bate, Cat. Amph. B. M. p. 318, pi. i. fig. 12. The first two segments of the pereion are shorter than the rest, which are subequal. The superior pair of antennas have the peduncle short, the flagellum uniarticulate, curved downwards at the extremity, and furnished along the inferior margin, for about two-thirds of its length, with auditory cilia. The inferior pair consist of a peduncle, of which two segments are visible, and a long slender multiarticulated flagellum. The first pair of gnathopoda are very short, not having the carpus anteriorly produced. The second pair of gnathopoda are not larger than the first, but having the inferior angle of the carpus anteriorly produced. The first two pairs of pereiopoda resemble each other ; the second pair is slightly the larger, having the meros and carpus broadly distended, the latter fringed along the inferior margin with a row of very fine short cilia, and a few long equidistant solitary hairs ; propodos and dactylos reduced in character to a biarticulate joint, that bends back to form a prehensile organ with the carpus. The third pair of pereiopoda are very long, quite as long again as the next suc- ceeding pairs, having the propodos and carpus subequal in length, and the former furnished on the anterior margin with a comb-like row of fine teeth ; dactylos short and slender. The two last pairs of pereiopoda are about half the length of the third pair. The posterior pair of pleopoda is long and simple. The telson is short and dorsally flat, having a central process on the under surface that lies between the basal joints of the posterior pair of pleopoda. Colour, orange. This species has been recently sent to us by Mr. Edward, who has taken several of different ages off the coast of Banff. 524 APPENDIX. AMP HI POD A. HYP ERIN A. HYPERIIDM. (Vol. II. p. 19.*) Genus— VIBILIA. Vibilia. Edwards, Ann. des Sci. Nat. t. xx. p. 386. Hist, des Crust. t. iii. p. 72. Spence Bate, Cat. Amph. B. M. p. 299. Lanceola? Sat, Proc. Acad. Phil. p. 317. Generic character. Cephalon small. Pereion smooth, not dis- tended. First two segments of the pereion short, the rest gradually increasing in length. Segments of the pleon a little deeper than those of the pereion. Eyes small. Antennas short ; superior pair terminating in a vertically compressed uniarticulate flagellum. First pair of gnathopoda small, slender, cylindrical, having the infe- rior angle of the carpus but little, if at all, produced ; second pair having the inferior angle of the meros and carpus considerably pro- duced anteriorly. First two pairs of pereiopoda subequally long. Third and fourth pairs longer than the preceding, subequal. Last pair very short. Three posterior pairs of pleopoda, with the peduncle long and the rami short and compressed. Telson single. VIBILIA BOREALIS, N.S. Specific character. Cephalon not anteriorly produced. Pereion with the segments gradually enlarged. Flagellum of upper antennse flat, with two rows of cilia on the internal surface. Last pair of pereiopoda minute. Length, seven-twentieths of an inch. APPENDIX. 525 The pereion has the first segment short, each segment gradually increasing in length posteriorly to the third segment of the pleon. The eyes are vertically of an oblong oval form. The first pair of antennae have the flagellum vertically and longitudinally flattened, the inner surface being furnished with two central rows of cilia, the cilia in one row being directed upwards, and in the other downwards. The second pair of antenna are slender, cylindrical, not longer than the superior, articulations variable. The gnathopoda are subequal, small. The first two pairs of pereiopoda robust, subequal. The third and fourth pair subequal, longer than the preceding, but not more than one-third ; propodos having the anterior margin fringed with fine rows of short teeth. The posterior pair of pereiopoda are scarcely half the length of the pre- ceding. The pleopoda are subequal, reaching beyond the extremity of the telson, having the approximate margins only of the rami fringed with short strong spines. Colour reddish orange spotted with black. Hitherto the species of this genus have been taken only as pelagic in tropical or subtropical latitudes. Tt is an interesting fact that this species should have been taken off the coast of Banff, from whence it was sent to us by that very successful observer, Mr. Edward, who in writing says : "I can say little as to its habits. I took eleven, and kept a few alive for a short time, but observed nothing in their manners beyond that which may be seen in the majority of species, I supplied them with plenty of sand, and also a few marine plants, but they neither seemed to be burrowers nor climbers, as they never went into the one nor appeared to care for the other. They, however, swam a little. This they do somewhat after the manner of Callisoma crenata ; or, in other words, they rise gradually from the bottom until they reach the top ; then putting on more power, they dash round and round the vessel. With close observation I observed that the superior antennae were kept pretty well up and very widely apart, whereas the inferior were always directed downwards. All the legs were kept doubled up. I never saw them stretched out. They would then sink once more to the sand at the bottom. Here they would rest, sometimes a few minutes, sometimes longer, 526 APPENDIX. when they would again repeat their voluntary evolutions. They did not, however, always rise to the surface. The journey was sometimes performed about midwater. They are, when alive, a most beautiful coloured species, variegated not unlike Urothoe elegans, and rivalling that animal in bright- ness of tints. I took one, however, that was all over a most brilliant red. I have been told that this species has never been found outside the Medusa. However this may be, all mine were. And what appears to be more extraordinary is, that, comparatively speaking, we have had no Medusas here this season (1865). During the months of July, August, and September I have seen them, generally, by hundreds and thousands. All that I have this year observed have been three." Mr. Edward also informs us that he has seen speci- mens of these crustaceans thrown on the shore in extraordinary large quantities. After a storm one night, he saw them form- ing a band an inch and a half broad to an inch and a half deep, for thirty yards along the beach. APPENDIX. 527 SUPPLEMENTAL NOTES. ALLORCHESTES NILSSONII. (Vol. I. p. 40.) The females of this species, and probably of all in the genus, have the second pair of gnathopoda, slightly larger than those of the first pair. Genus- MONTAGUA. (Vol. I. p. 53.) Dr. Camil Heller (Beitrage zur naheren Kenntniss der Amphipoden des Adriatischen Meeres ; Denkschr. Ak. Wiss. Wien, xxvi. p. 13) states that this genus is identical with Probolium of Costa. PHOXUS HOLBOLLT. ( Vol I. p. 143.) Mr. Edward has sent us from Banff a specimen that cor- responds with this species, except in having longer inferior antennae. We consider it the male form. PHOXUS PLUMOSUS. (Vol. I. p. 14C.) A specimen of this genus has been forwarded to us from Banff, by Mr. Edward, that corresponds with this species in general character, except in having very much longer lower antennas, as well as a long plumose posterior pair of pleopoda. We take it to be the male form. 528 APPENDIX. (EDICEROS PARVTMANUS. {Vol. I. p. 161.) Some specimens have been sent to us from the Shetlands by Mr. Gwynn Jeffreys, and from Banff, where they were taken by Mr. Edward, that so nearly correspond with this species, that we think they must be the male form. They differ from that described in having the upper antennas but little longer than the peduncle of the lower ; the lower antennae as long as the entire animal ; and the gnathopoda with hands some- what larger, but scarcely equal to the " very large " hands as described by Kroyer in his description of the genus. KROYERA ARENARIA. {Vol. I. p. 173.) A specimen of Kroyera has been sent to us by Mr. Robert- son, who found it in sand near low water in Kames Bay, Milport. It differs from K. arenaria in having the inferior antennae longer than the animal. It may, as Mr. Robertson suggests, be the male. ACANTHONOTUS OWENIT. ( Vol. I. p. 232.) We have no hesitation in referring this species to the Gam- marus corniger of Fabricius,* whose specific name has long priority over any of the other names quoted in the page above referred to, and must consequently be adopted instead of that employed by us. It is also identical with the Ejrimeria tricristata of Signor A. Costa (Mem. di Real. Accad. Sci. Napoli, i. tab. 2, f. 2, 1853). ATYLUS GIBBOSUS. {Vol. I. p. 248.) Specimens of this species have been sent to us by Mr. Robertson, who took them on three different occasions in Kames Bay, imbedded in sponge on the valves of Pecten oper- * Iter Norwag. d. 20 Aug.; Spec. Ins. i. p. 517 (1781); Mant. Ins. i. p. 334 (1787) ; Ent. Syst. ii. p. 517 (1793). APPENDIX. 529 cularis. From the position of the animals, they appear to have remained in one place while the sponge grew round them, and in some instances almost enclosed them. Mr. Eobertson remarks, " It may be a nice point to settle whether the sponge serves for shelter or for food." AMPHITHOE RUBRICATA. {Vol. I. p. 416.) This and all the species described in the pages from 416 to 493 belong to the section Domicola : the left-hand heading, " Amphipoda Natatoria," at the commencement of each genus and species, consequently requires correction, COROPHIUM LONGICORNE. (Vol. I. p. 494.) With reference to the passage quoted by us from M. Quatre- fages, Mr. Robertson writes to us : " In February last I had an opportunity of seeing C. longicorne at Dunbar, both at the mouth of the Clyde and in the bays, where there was no admix- ture of fresh water, at high water, having little doubt but that it is to be found on our shores all the year round. I have again seen it burrowing, which it does rather sluggishly. In this operation it brings the points of the long antennae together, and pushes them into the mud; the fore-feet assist in widening the hole, and in turning the mud sideways ; the hind-feet throw it backwards ; the tail is carried at an angle downwards, which it presses against the mud, and forces itself forwards. My experience leads me to think that they do not burrow very deeply. I find them plentifully in the soft surface mud, but when I remove that away to the depth of about three inches, I have not found them in the firmer sub- soil." Mr. Robertson has also kept them with Annelids in the same vessel until they died, without perceiving them attempt- ing to touch the worms. VOL. II. M. M. 530 APPENDIX. According to the rules of nomenclature recently laid down by the British Association for the Promotion of Science, the names of the sub-families adopted in this work should uniformly terminate in ina instead of ides. The Annals of Natural History for December, 1868 (Ser. 4, vol. ii., p. 411 — , and plates 21, 22, and 23), contain a Memoir by the Eev. A. F. Norman, in which the following species of Sessile-eyed Crustacea are described and figured : — 1. Haploops tubicola Lilljeb. (See our Vol. ii. p. 506.) 2. Tessarops (nov. gen. Norm.) hastata Norm. (? Tiron acanthurus Lilljeb. ? Syrrhoe bicuspis Goes.) Aberdeen coast. 3. Nicippe tumida Bruzel. (See our Vol. ii. p. 511.) 4. Eriopis elongata Bruzel. Sound of Skye. 5. Mcera Loveni Bruzel. Sound of Skye. 6. Mcera Batei Norm. (See our Vol. ii. p. 515.) 7. Helleria (nov. gen. Norm.) coalita Norm. Shetland, Moray Firth, and Firth of Clyde. 8. Microprotopus (nov. gen. Norm.) maculatus Norm. To- bermory, Isle of Mull. 9. Cirolana truncata, n. sp. Norm. St. Magnus Bay, Shetland. 10. Anilocra Mediterranea Leach, Desm. In rock pools at Herm. 531 ALPHABETICAL INDEX. The sectional and family names cure printed in capitals. The specific names are arranged alphabetically tinder each gene) The synonymical names of the genera are enclosed in brackets Page Aberrantia (Amphipoda) . ii. 28 Aberrantia (Isopoda) . ii. 116 Acantbonotus . i. 231 Owenii . i. 232 iEga bicarinata . monopbtbahna psora tridens JEgID^S iEgina JEro-spirantia Allorcbestes iinbricatus Nilssonii . . i. 40 (Amatbia) Amatbilla Sabini Ampelisca Belliana Gaimardii . laevigata Ampeliscides . Ampbilochus . manudens . Amphipoda (Ampbithoe) Ampbitboe albomaculata Gammaroides littorina . rubricata . Anceidje . Anceus Edwardii (Praniza) fuscata (Praniza) Halidaii . maculata (Praniza) maxillaris . &ii. 528 ii. 276 ii. 278 ii. 286 ii. 283 ii. 281 ii. 275 ii. 49 ii. 438 i. 38 i. 43 & ii. 527 359 359 361 125 i. 135 i. 127 ii. 504 i. 124 i. 179 i. 180 i. 1 i. 252 i. 416 i. 426 i. 427 i. 422 i. 418 ii. 168 ii. 170 ii. 201 ii. 197 ii. 203 ii. 199 ii. 187 (Anisocbeirus) (Anisopus) Anonyx . ampulla denticulatus Edwardsi Holbolli longicornis longipes minutus obesus Plautus Antbura . gracilis Anthurhle Aora gracilis Apseudes . Latreillii Talpa Aquaspirantia (Araneops) Arcturid^ Arcturus . gracilis intermedins longicornis (Armadillidium) Armadillo . vulgaris ASELLID^J Asellus . aquaticua . Atylus bispinosus . gibbosus . Swammerdamii Batbyporeia pelagica . ic name. Tage ii. 119 i. 416 i. 91 i. 116 i. 101 i. 95 i. 104 i. 91 & ii. 510 i. 113 i. 108 i. 98 i. Ill ii. 157 ii. %M- /&0 ii. 155 i. 279 i. 281 ii. 144 ii. 153 ii. 148 ii. 209 i. 125 ii. 359 ii. 361 ii. 373 ii. 371 ii. 365 ii. 492 ii. 492 ii. 493 ii. 313 ii. 341 ii. 343 i. 244 i. 250 248 & ii. 528 i. 246 i. 302 i. 309 532 INDEX. Batbyporeia pilosa Robertsoni (Bellia) . Bopyrio^: Boj)yrus . Squillarum Calliojte . Fingalli grandoculis Iseviuscula Ossiani Callisoma creuata Campecopea Cranchii liirsuta Caprella . acanthifera acutifrons sequilibra hystrix linearis lobata spinulata tuberculata typica Caprellid^ (Ceradocus) (Cerapodina) Cerapus abditus difforniis Cheirocratus mantis Chelura . terebans Chelurid>e Cirol ana . Cranchii spinipes Conilera . cylandracea Corophiid^ CoROPHIIDES Corophium Bonellii crassicorne longicorne Crangonyx i. 493 Page Page . i. 304 Crangonyx subterraneus . i. 327 i. 307 Cratippus . i. 484 i. 187 tenuipes . . i. 485 ii. 210 (Cratophium) . . i. 434 ii. 214 (Crossurus) . ii. 119 ii. 218 (Cryptoniscus) . . ii. 257 i. 258 Cryptothiria . ii. 257 i. 263 balani . ii. 267 i. 265 pygmsea . . ii. 261 i. 259 Ctamid^: . ii. 77 i. 261 Cyamus . . ii. 80 i. 119 Ceti . ii. 85 i. 120 gracilis . ii. 94 ii. 433 ovalis . ii. 91 ii. 436 Thompson i . ii. 96 ii. 434 (Cymadusa) i. 416 ii. 49 Cymodocea ii. 425 ii. 65 emarginata . ii. 428 ii. 60 truncata . ii. 426 ii. 71 Cyrtophium . i. 479 ii. 63 Darwinii . i. 481 ii. 52 Danaia . i. 67 ii. 57 dubia i. 68 ii. 74 Darwinia i. 182 ii. 68 compressa . i. 184 ii. 75 Dercothoe i. 459 ii. 35 punctatus . i. 461 i. 335 D examine i. 236 i. 452 spinosa i. 237 i. 452 tenuicornis i. 240 i. 455 Yedlomensis i. 242 i. 457 Domicola i. 414 ii. 513 Dryope . i. 487 ii. 513 crenatipalniata . i. 490 i. 205 irrorata i. 488 i. 503 Dulichia . ii. 30 i. 501 falcata ii. 33 ii. 294 porrecta ii. 31 ii. 296 DULICHIIILE ii. 28 ii. 299 Dynamene ii. 417 ii. 302 Montagui . ii. 423 ii. 304 rubra ii. 419 i. 414 viridis ii. 421 i. 478 (Dyopedos) ii. 30 i. 492 Eiscladus. i. 411 i. 497 longicaudatus i. 412 i. 499 (Elasmopus) i. 434 & ii. 529 Entoniscus ii. 265 i. 326 Porcellanse ii. 265 INDEX. 533 Page Page (Ericthonius) . . i. 452 Idotea emarginata . ii. 386 (Eupheus) . ii. 144 linearis . ii. 383 Eurydice . . ii. 307 parallela . . ii. 391 pulchra . ii. 310 pelagica . . ii. 384 Eurystheus . i. 353 tricuspidata . ii. 379 bispinimanus . i. 357 iDOTBIDiE. . ii. 375 erythrophthalmus . i. 354 lone . ii. 251 Eusirus . . i. 266 thoracica . . ii. 255 Helvetian . . i. 267 (Iphimedia) . i. 244 (Galanthis) . i. 45 Iphimedia . i. 217 Gammarella . i. 329 Eblanoe . i. 221 brevicaudata . i. 330 obesa . i. 219 Normanni . . i. 333 Issea . i. 214 GAMMARID.E . i. 51 Montagui . . i. 215 Gammarides . . i. 235 (Ischyrocerus) . . i. 434 Gammarina . i. 11 Isopoda . . ii. 99 Garnmarus . i. 366 (Itea) . ii. 454 campylops . . i. 375 Jsera . ii. 314 dubius . i. 397 albifrons . . ii. 317 Edwardsii . . i. 386 Nordmanni . ii. 320 locusta . i. 373 (Jseridina) . ii. 320 maculatus . . i. 399 Janira . ii. 335 marinus . . i. 370 maculosa . . ii. 338 nolens . ii. 19 (Jassa) . i. 434 pulex , i. 388 Kroyera . . i. 171 tenuimanus i. 384 altamarina . i. 177 (Gnathia) . . ii. 170 arenaria . i .. 173 & ii. 528 Gossea i. 276 brevicarpa . ii. 508 microdeutopa . i. 277 Ljsmodipoda . ii. 28 Grayia i. 151 (Lsetmatopbylus) . i. 479 imbricata . . i. 152 (Lalaria) . . i. 279 Gyge , ii. 223 (Larunda) . ii. 80 Galatheoe . . ii. 225 (Lembos) . . i. 287 Hippolytes . ii. 230 Lepidepecreum . . ii. 509 Haploops . . ii. 506 carinatum . . ii. 509 tubicola ii. 506 Lex^taspidia . ii. 331 (Hemioniscus) . ii. 257 brevipes . . ii. 333 (Hiella) . ii. 10 (Leptocbeirus) . . i. 297 Hyperia . ii. 10 Leptocbelia . ii. 132 cyanese . ii. 521 Edwardsii . . ii. 134 Galba ii. 12 (Leptomera) . , . ii. 36 oblivia ii. 16 (Leptothoe) . i. 348 prehensilis ii. 520 Lestrigonus . ii. 3 tauriformis ii. 519 exulans . ii. 5 Hyperiid^j ii. 2 Kinahani . . ii. 8 Hyperina ii. 1 Leucothoe . i. 269 Idotea . ii. 376 articulosa . . i. 271 acuminata . ii. 394 furina . i. 274 appendiculata . ii. 396 (Leucothoe) . i. 53 534 INDEX. Page 1 Page LlBERATICA ii. 313 Montagua marina i. 58 Ligia . ii. 442 monoculoides i. 54 oceanica . ii. 444 norvegica . ii. 500 Liljeborgia i. 202 pollexiana . i. 64 pallida i. 203 Munna . ii. 323 Sbetlandica i. 206 Kroyeri ii. 326 Limnoria . ii. 349 Whiteana . ii. 329 lignorum . ii. 351 IN DBScL » • • • ii. 430 (Liriope) . ii. 257 bidentata . ii. 431 (Liriopsis) ii. 257 Natatoria i. 50 (Loncbonierus) . i. 279 (Nanpredia) ii. 36 (Lycesta) . i. 269 Nicea . i. 45 Lysianassa i. 72 Lubbockiana i. 47 Atlantica . i. 82 Nicippe ii. 511 Audouiniana i. 79 tumida ii. 511 Costse i. 74 Nipbargus i. 311 longicornis i. 86 aquilex i. 315 Lysianassides . i. 71 fontanus . i. 931 Megamcera i. 400 Kocbianus. i. 323 Alderi i. 407 Noenia i. 471 brevicaudata i. 409 excavata . . i. 476 longimana . i. 403 riniapalrnata i. 474 multidentata ii. 515 tuberculosa i. 472 Othonis i. 405 undata , i. 477 semiserrata , i. 401 Normalia (Amplripoda) . i. 11 Melita i. 335 Normalia (Isopoda) . . ii. 208 gladiosa i. 346 (Nototropis) . i. 244 obtusata . , i. 341 CEdiceros . . i. 160 palmata . i. 337 parvimanus i. 161 & ii. 528 proxima . . i. 344 (Oliska ?) . ii. 163 (Microcheles) . . i. 217 Oxiscid^: . . ii. 439 (Microdeutopus) . i. 287 (Oniscoda) . ii. 335 Microdeutopus . . i. 287 Oniscus . . ii. 466 anomalus . , i. 293 asellus . ii. 468 fasciculatus . i. 295 fossor . ii. 472 gryllotalpa . i. 289 Opis . ii. 501 versiculatus , i. 295 leptocbela . . ii. 501 Websterii . . i. 291 quadrimana . ii. 503 (Mcera) . . i. 335 Orcbestia . i. 24 Mcera . i. 348 brevidigitata . ii. 497 grossimana . i. 350 Desbayesii i. 36 (Metoeclius) . ii. 10 littorea , i. 27 Monoculodes . i. 163 Mediterranea , i. 31 carinatus . . i. 165 ORCHESTIID.E . . i. 12 longirnanus ii. 50' J & ii. 527 Otus , i. 223 Stiinpsoni . . i. 168 carinatus . . i. 224 Montagua . i. 53 (Panope) . . ii. 80 Alderi . i. 61 Parantbura , . ii. 163 clypeata . ii. 499 Costana . ii. 165 INDEX. 535 Page Page Parasitica . ii. 209 Porcellio armadilloides , ii. 486 Paratanais . ii. 137 cingendus ii. 490 forcipatus . . ii. 133 dilatatus . ii. 479 rigidus . ii. 141 laevis . . , ii. 484 Pereionotus . i. 226 pictus . . , ii. 481 testudo . i. 223 pruinosus . , ii. 483 Phsedra . . i. 208 scaber ii. 476 antiqua . i. 209 (Praniza) . ii. 170 Kinahani . . i. 211 Protella . , ii. 44 Pherusa . . i. 252 pbasma ii. 45 bicuspis . i. 253 Proto , ii. 36 fucicola . i. 255 Goodsirii . . ii. 42 Pbiloscia . . ii. 448 pedata . ii. 38 Couchii . . ii. 452 Protomedeia . . i. 297 Muscorum . ii. 450 hirsutiinana . i. 298 Philougria . ii. 454 Wbitei . i. 300 riparia . ii. 456 (Pseudophtbalnms) . . i. 125 rosea . ii. 460 (Ptilocbeirus) . , i. 297 vivida . ii. 458 (Pyctilus) i. 452 Phoxides . i. 138 (Rbaea) . ii. 144 Pboxus . i. 139 Rocinela . . ii. 289 Holbolli . i . 143 & ii. 527 Danmoniensis . . ii. 129 plumosus . . i. 146 Saltatoria . i. 11 simplex . i . 140 & ii. 527 (Scopelocbeirus) . i. 119 Pbronima . ii. 21 Sipboncecetes . . i. 463 sedentaria . ii. 23 crassicornis . i. 469 Phronimid^jh . ii. 20 typicus . i. 465 Pbryxus . . ii. 232 Wbitei . . i. 467 abdominalis . ii. 234 (Slabberina) . ii. 307 fusticaudatus . ii. 238 Spbseroma . ii. 401 Galatbese . . ii. 249 curtum ii. 412 Hyndmanni . ii. 243 Hookeri . . ii. 410 longibrancbiatus . ii. 246 Prideauxianum . . ii. 415 Paguri . ii. 240 rugicauda . . . ii. 403 (Platopbium) . . i. 479 serratum . . ii. 405 Platyartbrus . ii. 462 Sphjeromid^i . . ii. 398 Hoffinannseggii . ii. 464 Sph^eromidea . . ii. 398 (Pleonexes) . i. 416 Stegocephalides . i. 51 (Pleurocrypta) . . ii. 232 Stimpsonia . i. 284 (Podalirius) . ii. 49 cbelifera . . i. 285 PODOCERIDEa . . i. 415 Sulcator . . i. 187 Podocerus . i. 434 arenarius . . i. 189 capillatus . . i. 442 Sunampbitboe . . i. 429 falcatus . . i. 445 conformata . i. 432 ocius . i. 450 Hamulus . . i. 430 pelagicus . . i. 447 Talitrus . . . i. 13 pulcbellus . i. 436 locusta . i. 16 variegatua . i. 439 Tanaid.e . ii. 117 Porcellio . . ii. 474 Tanais . ii. 119 536 INDEX. Tanais Dulongii vittatua (Tauria) . (Tetromatus) , Themisto . crassicornis (Thersites) (Typhis) . Unciola leucopes . Urotlioe . Bairdii brevicornis 487 ii. Page 129 • • ii. 125 • • 11. 10 i. 125 ii. 522 ii. 522 i. 302 ii. 19 & ii. 517 ii. 518 i. 192 i. 193 i. 198 Urothoe elegans i. Page 200 marinns . i. 195 Vagantia (Ainphipoda) i. 11 Vagantia (Lsopoda) . ii. 117 (Vertumnus) i. 231 Yibilia ii. 521 borealis ii. 521 (Westwoodia) . i. 154 "Westwoodilla . i. 154 ccecula i. 155 hyalina i. 158 (Zeuxo) . . ii. 119 (Zia) . ii. 448 AyL « tfc v;.; V :2C *H* r-22 ^p- tVM V 5