100 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 



as long as a segment, to the last dorsal, of which the length equals two 

 segments. These spines are flattened, especially the ventral spines; 

 the second and third are broadened in such a way as to become more 

 or less spatulate, though they are markedly less broadened than in 

 O. spatula; their tip is rounded. The dorsal spines are narrower than 

 those preceding, not broadened, and their extremity is pointed. All 

 these spines are provided with very fine and very closely placed 

 asperities. 



The tentacle scales are two in number on the pores of the first 

 pair, but single on all the following pores; these scales are large, 

 rounded, and a little longer than broad. 



Affinities and distinctive features. Up to the present time the 

 genus Ophiocopa was only known from a single species, 0. spatula, 

 dredged by the Blake in 150 fathoms in the Caribbean Sea. This 

 new species incontestably belongs to the same genus Ophiocopa, and 

 it is distinguished from 0. spatula by having the arm spines less 

 broadened and less strongly spatulate and by the single tentacle scale 

 beyond the pores of the first pair ; the external mouth papilla seems 

 to me also a little more broadened than in the Antillean species. The 

 discovery of a second species of the genus Ophiocopa in the Philip- 

 pine Islands is very interesting. 



OPHIOTHAMNUS VENUSTUS Matsumoto. 



Plate 23, figs. 3, 4. 



Locality. Albatross station 5619 ; Molucca Passage ; Mareh Island 

 (S.) bearing S. 78 E. 12.97 kilometers (7 miles) distant (lat. 35' 

 00" N., long. 127 14' 40" E.) ; 796 meters (435 fathoms) ; November 

 27, 1909 ;fne. gy. S., M. 



One specimen (Cat. No. 40934, U.S.N.M.). 



Notes. The specimen is not in a perfect state of preservation, and 

 the arms are incomplete; furthermore, the size is very small, the 

 diameter of the disk not exceeding 2.5 mm. The disk is pentagonal, 

 somewhat depressed in the center, and rather strongly notched in the 

 interradial spaces. The dorsal surface is covered with small imbri- 

 cated plates of which the outlines are only slightly evident ; each of 

 these plates carries a small conical club-spine, which is pointed, 

 rather thick at the base, and tapers rapidly to its extremity. The 

 radial shields are rather large, triangular, elongated, twice as long 

 as broad, in contact throughout almost their whole length and only 

 separated proximally by a small triangular plate. The ventral sur- 

 face is covered with rather large imbricated plates, which carry club 

 spines only toward the periphery of the disk. The genital slits are 

 narrow, but very evident. 



The mouth shields are small, triangular, a little broader than long, 

 with a sharp proximal angle and straight sides which pass over 



