NO. 1701. 



NORTHWEST PACIFIC ISOPODS— RICHARDSON. 



79 



segments do not extend beyond the posterior margin of the segment 

 and are quadrangular ; those of the last four segments have the outer 

 post-lateral angle produced so that they extend beyond the posterior 

 margin of the segment, each being increasingly longer. Each 

 epimeron is furnished on the outer post-lateral angle with a bunch of 

 long hairs, a most conspicuous feature. 



The first two segments of the abdomen are entirely concealed. The 

 three following are short and subequal. The terminal segment is 

 triangular, with apex rounded. The inner branch of the uropoda 

 IS about twice as wide as the outer branch and is a little longer. It 

 is widely rounded posteriorly and extends a 

 little beyond the tip of the abdomen. Both 

 branches, as well as the terminal segment of the 

 abdomen, are furnished with hairs and a few 

 spines. 



The first three pairs of legs are prehensile, the 

 other four pairs ambulatory. In the first pair of 

 prehensile legs the merus is armed with four 

 blunt spines, the car|)us with one, the propodus 

 with seven rounded teeth, and the dactylus with 

 four low rounded serrations. 



Only one specimen, a male, was collected at sta- 

 tion 4879, in the eastern channel of Korea Strait, 

 vicinity of Oki Shima, S. 70° W., 7.5 miles (lat. 

 34° 17' N.; long. 130° 15' E.), at a depth of 59 

 fathoms in fine gray sand and broken shells. 



This species is very close to Alcirona insularis 

 Hansen " from Samoa, but differs in the character of the prehensile 

 legs, in having a bunch of hairs on each epimeron at the outer post- 

 lateral angle, and in having the first two segments of the abdomen 

 entirely concealed. 



Type-specimen.— C2ii. No. 39498, U.S.N.M. 



Fig. 6. — Alcirona 

 NiPONiA. Leg op 



FIRST PAIR. X 27J. 



Family ^GID^. 

 Genus ^EGA Leach. 



.ffiGA SYMMETRICA Richardson. 



^ga symmetrica Richardson, Bull. U. S. Bureau of Fisheries, vol. 24, 1905, 

 pp. 211-212; Bull. U. S. Nat. Mus., No. 54, 1905. pp. 185-187. 



Localities. — Station 4771, on " Bowers Bank," Bering Sea, at lat. 

 54° 30' N.; long. 179° 17' E., and station 4772, at lat. 54° 30' 30" N. ; 



"Vidensk. Selsk. Skr. 6te Rsekke, naturvidenskabelig og mathematisk Afd., 

 vol. 5, pt. 3, 1890, pp. 393^395, pi. 8, figs. 2-2n. 



