PENJ3US CARAMOTE. 319 



rostrum, the posterior portion of which is also traversed by 

 a third longitudinal groove. A strong tooth at the anterior 

 margin of the carapace, above the insertion of the internal 

 antennas, and at the outer and upper margin of the orbit, 

 a smaller tooth at its inner side, and a third very small one 

 at the posterior termination of a small lateral groove which 

 passes backwards from the face of the second tooth. The 

 eyes are round and remarkably large. The inferior or in- 

 ternal antennae have two extremely short filaments, shorter 

 than the last two articulations of the peduncle. The scale 

 of the external antennae is somewhat narrower and evenly 

 rounded towards the extremity, and ciliated along its 

 anterior and inner margin. The external pedipalps are 

 pediform, gradually tapering to the extremity, and ter- 

 minating in a small acute finger. The first three pairs 

 of feet didactyle, increasing in length from the first to 

 the third, which is rather the longest of the five. The 

 hand of the first pair is the most robust, that of the second 

 rather the longest : the fourth and fifth pairs are simple. 

 The abdomen is much compressed, particularly posteriorly, 

 and rises to an acute carina for the greater part of its length 

 backwards. The fourth and fifth segments are notched on 

 each side. The last segment, or medium portion of the 

 tail, is long, narrow, triangular, acute, longitudinally 

 grooved, furnished with a strong tooth on each side near 

 the apex. 



The length of the British specimen, figured by Leach, 

 from the rostrum to the extremity of the tail is not more 

 than three and a half inches. Risso gives five inches, 

 and Milne Edwards seven as the length of those of the 

 Mediterranean. 



I have felt compelled, upon careful examination, to con- 

 sider the British species of Penaus, to which Leach, pro- 



