54 BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



507 fathoms, brown mud, fine sand, foraminifera, bottom tempera- 

 ture 39, 4 specimens; station 4981, Sea of Japan, lat. 42 58' 15" 

 N.; long. 140 9' 10" E., 390-406 fathoms, green mud, bottom tem- 

 perature 32.7, 49 specimens; station 4986, Sea of Japan, lat. 43 1' 

 40" N.; long. 140 22' 40" E., 172 fathoms, fine black sand, black 

 mud, bottom temperature 33.9, 1 specimen; station 4989, Sea of 

 Japan, lat. 43 23' 10" N.; long. 140 37' E., 92 fathoms, sand, 

 bottom temperature 39. 7, 1 specimen; station 4991, Sea of Japan, 

 lat. 45 23' 20" N.; long. 140 48' E., 325 fathoms, green mud, 

 bottom temperature 33, 1 specimen; station 4997, Gulf of Tartary, 

 lat. 47 38'40"N.; long. 141 24' 30" E., 318 fathoms, green mud, 

 bottom temperature 32.8, 4 specimens; station 5020, Okhotsk Sea, 

 lat. 48 32' 45" N.; long. 145 7' 30" E., 73 fathoms, green mud, 

 sand, pebbles, bottom temperature 30.9, 4 specimens; station 5021, 

 Okhotsk Sea, lat. 48 32' 30" N.; long. 145 8' 45" E., 73 fathoms, 

 green mud, sand, pebbles, bottom temperature 30.9, 3 specimens; 

 station 5026, Okhotsk Sea, lat. 48 36' 10" N.; long. 145 17' 30" E., 

 119 fathoms, green mud, black sand, gravel, bottom temperature 

 30.4, 1 specimen; station 5037, off the Hokkaido, Japan, lat. 42 2' 

 40" N.; long. 142 33' 20" E., 175-349 fathoms, bottom tempera- 

 ture, 37.9, 2 specimens; station 5082, off Omai Saki, Japan, lat. 

 34 5' N.; long. 137 59" E., 662 fathoms, green mud, fine sand, 

 globigerina, bottom temperature 37.7, 18 specimens; station 5083, 

 off Omai Saki, Japan, lat. 34 4' 20" N. ; long. 137 57' 30" E., 624 

 fathoms, green mud, fine sand, globigerina, bottom temperature 38.1, 

 85 specimens; Bering Sea, 60 specimens. Bathymetrical range, 67- 

 1,771 fathoms. Temperature range, 49.4 to 30.9. Two thousand 

 and thirty-seven specimens. 



Type. Cat. No. 25732, U.S.N.M., from station 3069. 



Although these two thousand specimens come from such widely 

 separated localities and such greatly different depths, they exhibit 

 surprisingly little diversity. There are slight differences in the num- 

 ber of disk scales and particularly in the conspicuousness of the centro- 

 dorsal and other primary plates, in the form of the oral shields, and 

 in the length and thickness of the arm spines ; but these peculiarities 

 are very insignificant and do not seem to be associated at all with 

 either locality or depth. In a few individuals from considerable 

 depths there are widely scattered, minute spines on the disk scales, 

 but other individuals from the same stations have none and the 

 peculiarity appears to be of no systematic importance. The geo- 

 graphical range of this species is extended but peculiar; on the 

 American coast it ranges from northern Oregon (lat. 45 30' N. ; long. 

 124 52' W.) to the western end of the Aleutian Islands (long. 174 

 13' E.) and northward into Bering Sea (lat. 55 35' N.); on the 

 Asiatic coast it was taken off eastern Japan, as far south as 33 35' 20", 



