NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM — CLARK. 229 



ing second, hexagonal, about as long as wide; succeeding plates sepa- 

 rated, more or less pentagonal, with rounded distal margin, longer 

 than wide. Side arm plates large, meeting above and below, each 

 with seven stout, smooth, not very sharp spines, of which the upper- 

 most is longest and exceeds two joints. Tentacle scales two on first 

 pair (or first two pairs) of arm pores ; after that single, but very large, 

 flat and oval. Color (dried from alcoliol), liglit grayish-brown or dirty 

 wliitisli. 



Fig. 107.— Ophiacantha atopostoma. x 5. n, from above; 6, from iselow; c, .side view of two 



ARM JOINTS NEAR DISK. 



Locality.— Albatross station 4772, Bering Sea, hit. 54° 30' 30" N.; 

 long. 179° 14' E., 344 to 372 fathoms, green-brown sand, bottom 

 temperature 38.1°, 1 specimen. 



Type.— Cat. No. 25599, U.S.N.M., from station 4772. 



Although this specimen is in very poor condition, the mouth parts 

 are so peculiar and characteristic that, taken in connection with the 

 disk covering, they warrant the description of a new species. I do 

 not know of any other with whicli it is likely to be confused, although 

 it resembles 0. stint ulea L3^man in many characters ; the exposed radial 



