APPENDIX, 



AMPHIPODA. 



NATATORIA. 



513 



GAMMARIDES, 



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 shoiter 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. 



CIIEIROCRATUS 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 



