632 CRUSTACEA. 



Atlantic ; latitude 2i north, longitude 111 west. Collected, Octo- 

 ber 29, 1838, at 4 o'clock, A. M. 



Length, one and three-eighths inches; breadth of carapax, one- 

 fifth of an inch. Whole body pellucid and colourless, except a reddish 

 tinge on posterior margin of last segment of body, and two or three 

 spots about the segments of the abdomen. Beak of carapax slender 

 and naked. Spinous process of anterior and posterior angles very 

 slender, appearing to be a continuation of the corneous edge of the 

 carapax ; a few short spines on these processes. Posterior margin of 

 carapax very nearly straight transverse, excepting the emargination 

 at centre. The breadth of the emargination is slightly greater than 

 that of the segment below, or about one-quarter that of the whole 

 margin itself. Median spinule situated as far from the margin as the 

 breadth of the emargination. 



The ophthalmic segment is separated from the antennary by a 

 distinct suture, and the two antennary are also distinct. The eyes 

 have very slender peduncles, a little curving, with spheroidal or 

 obconical extremities. The pigment is dark green, nearly black. 

 The anterior antennas have a three-jointed base ; first joint a little 

 the longest. Of the three branches, one, the largest in diameter, has 

 longish ciliaa on one side, and is shorter than the base of the antennas ; 

 the others are very slender and longer than the base. The inter- 

 mediate branch consists of seven joints, which are rather long except- 

 ing the last, which is quite short. The second antenna; have a slender 

 jointed appendage at base of second joint. The oval plate terminating 

 the organ is narrow elliptical and ciliated ; it is longer than the two 

 preceding joints together. 



The maxillipeds consist of three joints on a short base, the first two 

 broad, the last narrow, and all edged within with hairs or seta). Man- 

 dibles brownish red and corneous, toothed at extremity. 



First pair of legs very slender, extending forward nearly to base of 

 second antennae, five-jointed. Basal joint short. Second pair of 

 legs with a long narrow hand, broadest a short distance from apex 

 and gradually narrowing to a slender base. An emargination on 

 the outer side, about one-third the distance from the base to the 

 apex, into which the extremity of the finger shuts; and two spines 

 just above this emargination. Minute spinules or deuticulations 

 on the inner margin of the finger. Following three pairs of legs 



