ISOPODA OF THE 'LIGHTNING-' AND OTHER EXPEDITIONS. 81 



Diagnosis of Species of Apseudes here described. 



No rostrum, front truncate obtusifrons. 



Rostrum minute, simple, a mere point. 



Epistoma furnished with a spine talpa. 



Epistoma not furnished with a spine. 



Second gnathopods with an ordinary curved dactylus latreillii. 



Second gnathopods with a curiously twisted dactylus uncidigitatus. 



Rostrum long, acute, with a bulb-like swelling on each side of the base. 

 Bulbs convex in front. 



Carapace with a pair of large lateral spines gracilis. 



Carapace without lateral spines. 



Hand of second gnathopods ovate, not much longer than broad . spinosus. 

 Hand of second gnathopods elongated, linear, 3-4 times as long as 



broad simplicirostris. 



Bulbs concave in front bmarifrons . 



Rostrum tridendate, composed of three acute processes grossimanus. 



Besides the foregoing species, four other forms have recently been recorded by 

 Prof. G. O. Sars from the Mediterranean — Apseudes tenuimamis, acutifrons, robiishis, 

 and echinafiis. The last certainly comes very near to, and may prove to be identical 

 with, the Apseudes lunarifrons. A species has also been described by Studer from 

 Kerguelen Island, Apseudes spectabilis (Studer, ' Isopoden der Reise S.M.S. ' Gazelle ' 

 um die Erde, 1874-76,' 1884, p. 23, pi. i. fig. 9, a-g). 



1. Apseudes talpa (Montagu). 



Cancer [Gammarus) talpa, Montagu, Trans. Linn. Soc. ix. p. 98, pi. iv. fig. 6. 



Apseudes talpa, Leach, Ediub. Encyclop. vii. 1814, p. 404 ; id. Trans. Linn. Soc. xi. p. 372 ; id. Suppl. 



Enc. Brit. i. p. 428 ; Samouelle, Entom. Compend. p. 109 ; Lamarck, Hist. Nat. Anim. sans 



Verteb. (deuxieme edit.) v. p. 290 ; Latreille, Enc. Method, pi. cccxxxvi. fig. 26 ; Cuvier, Reg. 



Anim. edit. Latreille, pi. cliv. p. 124 ; edit. Crochard, Crust, pi. xlii. fig. 1 ; id. Anim. Kingdom, 



edit. Henderson, iii. p. 223, pi. xxxvi. fig. 4; Guerin, Icon. pi. xxvii. fig. 6 j Lucas, Hist. Nat. 



des Crust, p. 243; Milne-Edwards, Crust, iii. p. 140; White, Brit. Mus. Cat. Brit. Crust. 



p. 67 ; id. Pop. Hist. Brit. Crust, p. 226 ; Gosse, Marine Zool. i. p. 136, fig. 245 ; Bate and 



Westwood, British Sessile-eyed Crust, ii. p. 148 ; G. 0. Sars, Revision af Gruppen Isopoda 



Chelifera, 1880, p. 10. 

 ? Eupheus ligioides, Risso, Crust, de Nice, 1816, p. 124, pi. iii. fig. 7 ; Hist. Nat. de I'Europe Merid. 



v. p. 99 ; Desmarest, Consid. gen. Crust, p. 285 ; Milne-Edwards, Crust, iii. p. 143. 

 Eupheus talpa, Dcsm. Consid. gen. Crust, p. 285. 

 ? Apseudes ligioides, Lucas, Hist. Nat. Crust, p. 243 ; Lamarck, Anim. sans Verteb. (2° edit) v. 



p. 291. 



Rostrum triangular, acute. Ocular alae obtuse. Eyes well developed. Segments 

 of perseon narrower than carapace, each having a short triangular process at the latero- 



