of the Division Hyperina. 5 



margin parallel with the anterior; distal extremity rounded; 

 internal surface concave, near the centre of which the suc- 

 ceeding joints articulate, but altogether they are not more than 

 one-fourth the length of the basos, and are serrated upon 

 the flexible margin. Fifth pair of pereiopoda represented by a 

 membranous scale, not unlike one of the branchise, but fur- 

 nished at the extremity with a small tubercle. Three anterior 

 pairs of pleopoda biramous ; three posterior also biramous, but 

 each ramus is developed into the form of a broad, thin, membra- 

 nous plate. Telson as broad at the base as the preceding 

 joint, and terminating obtusely. 



Length f of an inch ; of young, ^ of an inch. 



Habitat unknown. Taken by M. Morrisse of Havre. 



Having given a description of the form of the adult animal, it 

 will be interesting to compare it with that of the young before 

 it has quitted the care of the mother. 



Auimal long and narrow. Cephalon anteriorly produced, the 

 apex recurved beneath. Superior antenna? nearly as long as the 

 cephalon, two-jointed, and tipped with four hairs neai-ly as long 

 as the last joint. Inferior antennae single-jointed, the extremity 

 tipped with four hairs. First pair of gnathopoda having the 

 meros and carpus broadly developed, with the inferior angle of 

 each rounded-off and furnished with a solitary hair; propodos 

 not half so broad as the carpus, increasing in diameter towards 

 the distal extremity, where a small concave palm is apparent ; 

 dactylos long and sharp. The second pair are uniform with the 

 first. First pair of pereiopoda longer than the gnathopoda, 

 simple in character, and having the meros, carpus, and propodos 

 each furnished with a single hair at the infero-distal extremity. 

 The second pair of pereiopoda are uniform with the first. The 

 third pair is about the same length as the preceding, but having 

 the basos broadly developed, increasing in diameter towards the 

 distal extremity, where it is produced posteriorly beyond the 

 point at which it articulates with the ischium; the ischium, meros, 

 and carpus are all broadly developed, and the two latter are fur- 

 nished with a single hair at the antero-distal angle ; the pro- 

 podos is very narrow, and the dactylos long. The fourth pair 

 of pereiopoda are uniform with the third. Fifth pair as long as 

 the preceding, having the basos long and narrow, being scarcely 

 dilated at all, and the remaining joints, which articulate at the 

 extremity of the basos, fully developed, except the dactylos, 

 which exhibits the appearance of an arrest of development, 

 forming, apparently, a rim round the extremity of the preceding 

 joint. Three anterior pairs of pleopoda present, but not de- 



