CRUSTACEOLOGY. 



433 



Appendix. ** Superior antennae shorter than the under ones ; 

 "*" "y*" the last joint scarcely articulated. 



Genus XI. Podocerus. Eyes hemispherical and 

 somewhat prominent ; four anterior feet didactyle, an- 

 terior pair smallest with an elongate-subovate hand ; 

 second pair with an ovate hand, and the internal side 

 nearly strait. 



Sp. 1 . Variegatus. Body, legs, and antennas beauti- 

 fully variegated with red. 



Podocerus variegalus. Leach's MSS. 



Inhabits the rocky shores of Devon, walking about 

 en fuci and corallines with its antennas as well as legs. 



Genus XII. Jassa. Eyes not prominent; four an- 

 terior feet didactyle with ovate hands ; the anterior 

 pair smallest ; the hand of the second pair with the in- 

 ternal edge furnished with teeth. 



Sp. 1. Pulchella. Thumb of the second pair with 

 the internal edge emarginate at the base. 



Var. «.. Internal edge of the hand of the second pair 

 of feet with an elongated tooth at the base. 



Var. /3. Internal edge of the second hand with three 

 teeth. 



lassa pulchella. Leach, Mem. Wern. Soc. vol. ii. 



Inhabits fibrous fuci on the Devonshire coast every 

 where. White painted with red. 



Sp. 2. Pelagica. Hand of the second pair with the 

 internal edge having a lunar notch. 



Iassa pelagica. Leach, Mem. Wern. Soc. vol. ii. 



Received through 'Mr Stevenson's kindness from the 

 Bell Rock, in the German Sea. 



Cancer gammartis falcatus of Montagu. Lin. Tn ns. 

 vol. ix. tab. 5. fig. 2. seems referable to this genuf. 



Tribe III. PHRONIMARIDES. 



Extremity of the tail furnished with several styles ; 

 feet ten. 



This tribe contains the genus Phronima, mentioned 

 in p. 403, which might constitute a distinct family. 



Trir^ IV. CAPRELLIDES. 



This includes our family Caprellini, to which we 

 can add another genus, differing from Caprella in having 

 true legs instead of the gelatinous fine-like legs, which 

 is naved. 



Gen. Proto. 



Sp. 1. Pedata. 



Cancer gammarus pedatus. Montagu, Linn. Trans. 

 vol. xi. p. 6. tab. ii. fig. 6. - 



Tribe V. APSEUDIDES. 



Comprehending our family Apseudii, p. 404. 

 Tribe VI. ASELLIDES. 



Antennae four, distinct ; last segment of the tail long. 

 Family I. Anthurid^e. 



Last segment of the tail very short, the last narrow, 

 elongate, with two elongate lamellae on each side ; an- 

 tennas nearly equal, inserted one behind the other in 

 nearly an horizontal line. 



Genus II. Anthura. See Genus LXV. 

 Family II. CymothoidjE. 



Last segment of the tail with one or two appendages 

 on each side ; antennae placed in pairs, one above the 

 other. 



Stirps 1. Last segment of the tail on each side with 

 a single appendage. 



Genus III. C vmpecopea. See Genus LXIX. 



Genus IV. Nes,ea. See Genus LXVIII. 



Stirps 2. Last segment of the tail with two appen- 

 dages on each side. 



VOL. vii. part ir. 



* Upper antennas with a very large peduncle ; head Appendix, 

 behind bilobate, the eyes placed on the lobes. w "V""' 

 Genus V. Cymodoce. Eyes touching the anterior 

 margin of the first segment ;"' base of the tail on each 

 side with two equal slightly compressed (but not folia- 

 ceous) appendages, exterior ones largest ; last segment 

 emarginate, with a lamella in the middle ; nails bifid. 

 Sp. 1. Truncala. Apex of tail truncate. 

 Inhabits the coast of Devon amongst fuci, but is 

 very rare. Leach's MSS. 



Oniscus truncatus, Montagu's MSS. 

 Genus VI. Dynamene. Eyes not reaching the an- 

 terior margin of the firs . segment ; base of the tail on 

 each side with two equal foliaceous appendages, apex 

 of the tail emarginate ; nails bifid. 



There are several indigenous species of this genus, 

 but the characters are not yet determined. 



Genus VII. SphyERoma. Eyes not reaching the an- 

 terior margin of tiie first segment ; last joint of the tail 

 entire, the base on each side furnished with two equal 

 foliaceous appendages ; nails bifid. 



Sp. 1. Serrata. Add to the character given in p. 405. 

 " External foliaceous appendage of the tail externally 

 serrated." 



Sp. 2. Rugicauda. Add, " foliaceous lamella? not ser- 

 rate externally." 



Sp. 3. Hookeri. Last joint of the tail with two ob»- 

 long obsolete tubercles. 



pheroma Hookeri. Leach, Metn. Wern. Soc. vol. ii. 

 Discovered by Mr W. J. Hooker on the Norfolk coast. 



** Peduncle of upper antennas not very large. 

 Genus VIII. Cymothoa. Head narrower than the 

 first segment of the body, and received into a notcn 

 in that part ; eyes obscure ; tail narrower than the body, 

 the last segment of the tail transversely quadrate, with 

 two styles on each side at the base. 

 Sp. 1. CEstrum, page 405. 



Genus IX. Limnoria. Head as broad as the first 

 segment of the body; eyes granulated and distinct; 

 tail scarcely narrower than the body ; last segment of 

 the tail rounded at the apex ; the base in each side with 

 two styles. 



Sp. 1 . Terebrans. Body cinereous ; eyes somewhat 

 pitchy-black. 



Limnoria terebrans. Leach, Mem. Wern. Soc. vol. ii. 

 Length from one line to two. 



This new and higldy interesting species was sent to 

 Dr Leach by Mr Stevenson, from the Bell Rock, in 

 logs of wood, which it perforated in the most alarming 

 manner. He has since received it from the coast of 

 Suffolk. It generally produces seven young ones. 

 Family III. Asellid^e. 

 Last segment of the tail very large ; middle antennas 

 very short ; external antennas half the length of the 

 body, or more. 



Stirps 1. Tail with two styles at the apex ; antenna? 

 filiform. 



Genus X. Idotea. External antennas half the length 

 of the body, or scarcely longer, the third and fourth 

 joints equal ; body ovate. 

 Sp. 1. Entomon, see p. 404. 

 Sp. 2. (Eslrum, see p. 404. 



Genus XI. Stenosoma. External antennas longer 

 than the body, the third longer than the fourth joint ; 

 body linear. 



Sp. 1. Hcclica. Apex of the tail truncate. 

 Idotea heclica of this article. See page 404. 

 Sp. 2. Acuminata. Apex of the tail acuminate. 

 Stenosoma acuminata. Leach, Mem. Wern. Soc. vol. ii. 

 3 i 



