392 IDOTEID^E. 



being soldered in the middle with, the large terminal 

 joint, of which the posterior portion is subobliquely 

 deflexed, with the extremity rounded, without any 

 appearance of terminal or lateral points. The upper 

 antennae consist of four short but very robust joints, an- 

 gulated at the margins. The outer antennae are about 

 one-fourth of the length of the entire animal, composed 

 of a peduncle consisting of five robust joints, followed by 

 a flagellum composed of three or four joints more or less 

 closely soldered together. The legs are of nearly equal 

 size, except the first, which is the largest ; the coxse or 

 epimeral portion of the second, third, and fourth pairs 

 appear dorsally as very narrow marginal plates, but in 

 the three posterior pairs they are much more developed 

 and visible from above, forming the lateral margin 

 of each joint, with the posterior angle produced into 

 a sharp elongated point. The first pair of legs are the 

 most robust, the third pair the longest, and the fourth 

 pair the shortest. 



The animal is obscurely coloured, greyish-buff, with 

 three longitudinal dusky lines, one down the middle of 

 the back and the other two lateral. 



This species appears to us to be very closely allied to, 

 if not identical with, the genus Cleantis of Dana (Expl. 

 Exped. Crust, p. 707, pi. 46, f. 9 ; the type of which 

 C. linearis was taken was from the stomach of a Silurus, 

 in the Rio Negro, North Patagonia), the characters of 

 which appear insufficient to warrant its separation from 

 Idotea. 



We have obtained this species from Falmouth, taken 

 by Mr. Barlee, and from Polperro, whence it was sent to 

 us by Mr. Loughrin. 



The Hopeian Collection contains numerous dry speci- 

 mens, to which the label " Naples " is attached ; they 



