1818.] CRUSTACEA OF THE UNITED STATES. 249 



pendages of the tail, with two moveable, prostrate, conic 

 spines placed each side in cavities; tip truncated and fur- 

 nished with four moveable spines, of which the interior 

 ones are much more elongated, and separated by an im- 

 moveable shorter one in the middle; interior antenna 

 about half as long as the exterior ones, the short seta 

 ciliate with long, parallel, equidistant hairs; colour whit- 

 ish, almost pellucid, with a few dark points, eyes dark, 

 peduncles spotted with yellow. 



Length from the end of the rostrum to the tip of the 

 tail, one inch and two fifths. 



This species is one of those which pass under the 

 name of Shrimps but they all diflfer specifically, as this 

 does generically, from the true shrimp of Europe. It is 

 congeneric with the European Prawn^ and in point of 

 form resembles it much, but that arrives to the length of 

 five inches. Found as far south as East Florida. 



2. P. * tenuicornis. Rostrum with about eleven or 

 twelve teeth above, and six or seven beneath; fingers of 

 the larger feet rather longer than the palm of the hand. 



Inhabits the Banks of Newfoundland. 



Rostrum as long as the plates of the antennae, densely 

 ciliated between the teeth; spines of the thorax, and of the 

 peduncles of the antennae, placed as in the preceding spe- 

 cies; carpus of the first pair of feet unarmed, and hardly 

 longer than the hand, fingers linear, a little reflected, as 

 long as the palm; carpus of the second pair as long or 

 rather longer than the palm of the hand, fingers a little 

 longtr than the palm and reflected; antennae Very slender, 

 white, interior ones more than two thirds of the length of 

 the exterior ones. 



