84 



PROCEEDINGS OF THE NATIONAL MUSEUM. 



vol. 37. 



second antennas extend to the posterior margin of the second thoracic 

 segment ; the flagellum is composed of sixteen articles. 



The first, second, and seventh segments of the thorax are about 

 equal in length ; the third, fourth, fifth, and sixth are slightly longer. 

 The epimera of the second and third segments are posteriorly rounded ; 

 those of the four following segments are posteriorly acute, and in the 

 last three segments are produced beyond the posterior margins of 

 the segments. 



The first segment of the abdomen is covered in the middle by the 

 last thoracic segment, but is visible at the sides; the three following 

 segments are subequal; the fifth segment is narrower than any of 

 the preceding segments, but is longer in the middle portion of the 

 dorsal surface. The sixth or terminal segment is posteriorly tri- 

 angulate, with the margin furnished with short spines and hairs. 



The uropoda do not extend beyond 

 the extremity of the abdomen; the 

 outer branch is slightly shorter and 

 slightly narrower than the inner 

 branch; they are both armed with 

 spines and furnished with hairs. 

 The posterior extremity of the inner 

 branch is more rounded than the 



Fig. 10. — Rocinela niponia. Third leg. outer branch 

 X 14*. * 



The propodus of the first pair of 

 prehensile legs is produced in a palmar process furnished with a 

 marginal row of ten curved spines; the two following pairs of legs 

 have eight spines on the propodus; the carpus is furnished with one 

 long spine; the merus is furnished with five long spines, the most 

 anterior one being very long, almost twice as long as the others. The 

 last four pairs of legs are also furnished with numerous spines. 



Only one specimen^ a female, was collected at station 4815, on the 

 way from Hakodate, Japan, to Ebisu, Sado Island, Sea of Japan, at 

 Niigata Light, S. 25° E., 21.5 miles (lat. 38° 16' N. ; long. 138° 

 52' E.), at a depth of 70 fathoms, in dark green sand. 



This species is very close to Rocinela propodialis Richardson, but 

 differs in having 10 spines on the palmar process of the propodus of 

 the first pair of legs and 8 on the next two instead of 6 teeth; in 

 having five long, sharp spines on the merus instead of five low, blunt 

 ones ; in having the posterior margin of the abdomen triangulate in- 

 stead of rounded; and in having the last three epimera produced 

 beyond the posterior margins of the segments instead of only the last. 



Type-specimen.— Cat. No. 39501, U.S.N.M. 



