76 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 37. 



On the ventral side of the head the anterior margin is provided 

 with four spines on either side close to the antenna? and within them. 



The first segment of the thorax is short and 

 narrow and almost inconspicuous. The sec- 

 ond segment is about half as long as the third, 

 but is equally wide. The second is covered 

 with small spines and tubercles, the third at 

 the sides and on the posterior half. The 

 fourth segment is a little longer than the 

 third and a little narrower; it is also fur- 

 nished with tubercles. The fifth segment is 

 one and a half times longer than the fourth 

 and has only a very few tubercles on the 

 dorsal surface. The sixth segment is a little 

 shorter and a little narrower than the fifth 

 segment and is furnished with but few tuber- 

 cles, more, however, than on the fifth segment. 

 The seventh segment is short and almost in- 



Fig. 1. — Gnathia tuber- 

 culata. Head and 

 thorax. x 14j. 



Fig. 2. — Gnathia tuberculata. 

 Anterior margin of head 

 (ventral). X 27h. 



conspicuous. 



The abdomen is abruptly about half as wide 

 as the sixth thoracic segment. The five ante- 

 rior segments are subequal. The terminal 

 segment is produced to a long, narrow extremity. The inner angle of 

 the peduncle of the uropoda is produced and extends about half the 

 length of the inner branch. The branches 

 are similar in shape and size, the inner one 

 being a little longer than the outer and also 

 a little longer than the tip of the terminal 

 segment of the abdomen. Both are fringed 

 with long hairs. 



The fourth- pair of 

 legs have the basis 



furnished with two long spines, one being at the 

 distal extremity and the other about the middle; 

 the ischium is furnished with one spine and the 

 merus with one. The fifth pair have the basis 

 furnished with three spines on the exterior mar- 

 gin ; the ischium is furnished with one spine and 

 the merus with one. The sixth pair have the 

 basis furnished with four spines. (The rest of 

 the leg is lost in the only specimen.) The first 

 pair of legs are modified into an operculum cov- 

 ering the mouth parts; each appendage is com- 

 posed of three articles, the last one being minute. 

 Only one specimen, a male and imperfect, comes from station 4831, 

 on the way from Nanao, Hondo, Japan, to Isuruga, Hondo, Japan, 



Fig. 3. — Gnathia tu- 

 berculata. ab- 

 DOMEN. X 27|. 



