1818.] OF THE UNITED STATES. 597 



3. C, impressed. Body oblong; head attenuated, ter- 

 minating acutely between the bases of the antennae j tail 

 with the terminal segment widely emarginate at tip and 

 as long as the five preceding segments conjunctly. 



Inhabits . 



Cabinet of the Academy. 



Body oblong; first, second, third and fourth segments 

 contracting by desiccation, their posterior margins re- 

 maining elevated and glabrous in consequence of the 

 more crustaceous consistence of those parts; seventh seg- 

 ment snort, very much lunated to receive the abdominal 

 segments, which with the two first of the tail are so ap- 

 proximated, as to appear on each side like lines; termi- 

 nal segment shorter, and more depressed in the middle 

 so as to appear almost bilobated, tip widely emarginated, 

 ndt longer than the five preceding segments conjunctly; 

 head attenuated to the tip, which is acute between the 

 bases of the superior antennae, which are very robust 

 and nearly attain the anterior segment of the body; eyes 

 conspicuous, granulated, marginal, oval; y^'^^ gradually 

 longer to the fifth pair, which are longest, sixth and se- 

 venth pairs equal to the fourth. 



Length one inch. 



This specimen was presented to me by Mr. Titian 

 Peale, who remarks that it was taken at Cape-may, New- 

 jersey. Can this be synonymous with C. ichtyola of Mr. 

 Latreille? 



4. C. lanceolata^ . Body oblong-oval; head broader 

 tlian long; tail dilated-lanceolate, carinate, equal to the 

 six preceding segments conjunctly. 



Inhabits . 



Vol. I. LI 



