30 BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



166 48' 50" W., 350 fathoms, mud, 11 specimens; station 3480, 

 Bering Sea, lat. 52 6' N. ; long. 171 45' W., 283 fathoms, black sand, 

 coral, rocky, 1 specimen; station (?), 1 specimen. Bathymetrical 

 range, 72 to 350 fathoms. Temperature range, 41 to 38.5. Twenty- 

 four specimens. 



Type. Cut. No. 25643, U.S.N.M., from station 2842. 



This species is even more Ophiacantha-like than the preceding and 

 I believe its natural relationships are with that genus. But it is so 

 obviously congeneric with Opltioconis miliaria and antarctica that 

 I am obliged to place it in OpTiioconis, at least for the present. The 

 resemblance to antarctica is particularly marked in a specimen which 

 has apparently at some time lost its disk; the regenerated disk, which 

 is still incompletely developed is covered by coarse granules, almost 

 exactly like those of the disk of antarctica. But papillata may always 

 be distinguished from antarctica, aside from the disk covering, by its 

 more triangular upper arm plates, the more spiniform granules of 

 the mouth angles, and the fewer arm spines. 



Family OPHIOLEPIDID^E. 



OPHIOPLOCUS IMBRICATUS. 



Ophiolepis imbricata MULLER and TROSCHEL, Sys. Ast., 1842, p. 93. 

 Ophioplocus imbricatus LYMAN, 111. Cat. Mus. Comp. Zool., 1865, p. 69. 



There is a single, well-preserved specimen from Okinawa, the 

 principal one of the Riu Kiu Islands. This appears to be about the 

 northern limit of this Indo-Pacific species, which is replaced to the 

 northward by the following closely related but quite distinct form. 



OPHIOPLOCUS JAPONICUS, new species." 



Disk 18 mm. in diameter; arms 66 mm. long. Disk closely cov- 

 ered with small scales, largest in the vicinity of the radial shields; 

 primary plates scarcely distinguishable, but on each interradial mar- 

 gin are seven plates larger than the others, the middle one being the 

 largest of the seven. Radial shields bare, but very small and widely 

 separated. Upper arm plates broken up into a considerable number 

 of plates, of which one at each side and five along the proximal border 

 of each arm joint are the largest. Interbrachial spaces below covered 

 with a close scaling, which is finest along the genital slits and close to 

 the oral shield. Genital slits long, extending from the oral shield 

 more than halfway to disk margin. Oral shields more or less pentag- 

 onal, about as long as wide, with all angles, except most proximal, 

 rounded. Adoral plates, meeting within, somewhat wider at outer 

 than at inner end; oral plates well marked, but smaller than adoral. 

 Oral papilla- about five on each side, the penultimate much the widest; 



a Japonicus signifying belonging to Japan, in reference to the apparently limited 

 geographical distribution. 



