IDOTEA ACUMINATA. 395 



instead of each of the joints being rounded at the sides, 

 and causing that part of the animal to he wider than its 

 tail. 



The eyes are placed in the middle of the lateral 

 margins of the head, the anterior-lateral angles of which 

 are considerably porrected ; the outer antennae are about 

 half the length of the animal, with the flagellum multi- 

 articulate and longer than the peduncle. The epimeral 

 base of the second, third, and fourth pairs of legs are 

 visible dorsally on the anterior-lateral angles of the seg- 

 ments to which they respectively belong, whilst they are 

 more distinct in the three posterior pairs, and occupy 

 the posterior-lateral angles, which are rounded off. The 

 tail is narrower than any of the segments of the body, 

 and is nearly cylindrical, with the extremity pointed, the 

 middle of the back forming a slight ridge. This part of 

 the body appears to consist of a single joint, but on 

 carefully examining its sides (near the base), traces will 

 be observed of two incisions, indicating two obliterated 

 basal joints. 



The British Museum specimens are from Dr. Leach's 

 Collection, taken in Devonshire. Mr. W. P. Cocks 

 found it in trawl refuse, at Gwyllyn Vase, Falmouth ; 

 there are several specimens in fine preservation in 

 the Hopeian Collection at Oxford, labelled, " South 

 West Coast of England," and we have received it from 

 Cumbray, from Mr. Robertson of Glasgow. 



This species is also given in the List of British Isopoda, 

 in the Reports of the British Association for 1860, p. 225. 



