2208 CRUSTACEA. 



Cephalo thorax slender, venter not carinate. Conspicilla large, very 

 nearly in contact. Anterior antennae short setulose. Finger of 

 the posterior antennae extremely slender and longer than the pre- 

 ceding joint, seta of the second joint long, setulose. Abdomen one- 

 jointed, narrow at base, linear apex half shorter than the preceding 

 elliptical part. Caudal stylets much shorter than the abdomen, 

 setae very short. 



Plate 85, fig. la, animal, enlarged, lateral view; a', upper view, 

 antennae not finished; b, anterior antenna; c, posterior antenna; d, 

 second or third pair of natatories. 



Atlantic, latitude 1° 30' north, longitude 18° 20' west, October 31, 

 1838 ; also, latitude 2° 20' south, longitude 20° west, November 6, 

 1838. 



Length, one-thirtieth of an inch. Colourless, except along the 

 venter, which is blue, and a little blue in the abdomen. 



This is a very slender species compared with other Corycaei, and is 

 remarkable for the slight prominence of the ventral angle. In an 

 upper view, the cephalo thorax is much the broadest at the head and 

 quite narrow behind; the two conspicilla occupy the whole front. 

 The posterior angles are slender acute. The anterior antennae have the 

 second and fifth joints longest. The setae are not more than half the 

 length of the antenna. 



The posterior antennae may possibly have a naked seta also to the 

 second joint; but only the setulose one was observed; this one is 

 about as long as the second joint. The finger has a very fine extre- 

 mity. The first joint of the finger was not accurately made out. 



The four pairs of natatories have each three-jointed branches. 



The minute eyes between the prolate lenses were observed. 



The abdomen in a lateral view has a very abrupt rectangular nar- 

 rowing on the under side, near middle. The caudal stylets are about 

 half as long as the abdomen, and the setae less than half the stylets. 



CORYCJSUS DECURTATUS. 

 Cephalothorax ventre carinatus. Conspicilla fere contigua. Antenna 



