72 



PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxv. 



The first segment of the thorax has the lateral margins produced 

 in one triangular process on either side, directed anteriorly; the 

 second, third, and fourth segments are each produced on either side 

 in two triangular processes, one anterior and 

 the other posterior; the last three segments 

 have the lateral margins produced on either 

 side in one long process directed posteriorly, 

 with a rudimentary posterior process indicated 

 on the posterior margin. 



The abdomen has the post-lateral angles 

 produced in one long acute triangular process 

 on either side of a small median rounded lobe. 

 The uropods have the basal article about equal 

 in length to the post-lateral angles of the ab- 

 domen; the inner branch is almost as long as 

 the basal article; the outer branch is a little 

 shorter. 



The first pair of legs are prehensile ; all the 

 others are ambulatory and furnished with bi- 

 unguiculate dactyli. 



The single specimen is a male, and comes 

 from Station 2116, off Cape Hatteras. It was 

 collected at a depth of 888 fathoms in blue mud 

 and fine sand by the U. S. Bureau of Fisheries' steamer Albatross. 

 The type is in the U. S. National Museum. Cat. No. 38963. 

 This species is very similar to Iolella spinosa (Harger), and differs 

 chiefly from that species in lacking spines on the dorsal surface of 

 the body. 



Genus RHACURA, new. 

 Head without rostrum, but with a triangular median frontal proc- 

 ess. Lateral margins of head with two triangular processes; eyes 

 small, but distinct. First pair of antennae with a peduncle of three 

 articles and a multi-articulate flagellum; second pair of antenna? 

 with the third article of the peduncle furnished with an antenna! 

 scale. 



First and fourth thoracic segments with one lateral process on 

 either side ; second, third, fifth, and sixth segments with two lateral 

 processes; seventh thoracic segment with three lateral processes. , 



Abdomen furnished with four lateral triangular processes on either 

 side. 



Legs as in the genus Iolella. 



This genus differs from Acanthaspidia Stebbing," the type of 

 which is Acanthaspidia typhlops (Sars), b in the presence of eyes, 



Fig. 1. — Iolella glabra. 



a Acanthaspidia Stebbing—Acanthoniscus Sars, Hist. Crust., 1893, p. 378. 

 1 Norwegian North-Atlantic Expedition, XIV, Zoology, Crust., I, 3885, 

 119-121, pi. x, figs. 27-30. 



pp. 



