256 



BULLETIN 15, UNITED STATES NATIONAL MUSEUM. 



more or less indistinct. Side arm plates very low, rounded, each 

 with a single, short blunt spine, not one-third as long as joint; under 

 the microscope this spine is seen to have the hook-shape so character- 

 istic of Cladophiurse. Tentacle pores distinct, but tentacle scales 

 entirely wanting. Color (dried from alcohol), pale yellowish. 



Locality. — Albatross station 34S0, Bering Sea, lat. 52° 6' N.; long. 

 171° 45' W., 283 fathoms, black sand, coral, rocky, 1 specimen. 



Type.— Cat. No. 25735, U.S.N.M., from station 3480. 



Further material of this interesting ophiuran will be necessary 

 before its real relationships can be positively determined. There is a 

 possibility that the type-specimen is immature. The single oral 

 shield present may very likely be the madreporite. 



Family OPHIOCOMID^. 



OPHIOMASTEX MIXTA. 



Ophiomastix mixta Lutken, Add. Hist. Oph., pt. 3, 1869, p. 44. 



Locality. — Tanegashima, Japan, 1 specimen. 



Although this species was described forty years ago, it has never 





Fig. 126.— Ophiomastix mixta, x 3. a, from above; 6, from below; c, side view of two arm 



JOINTS NEAR DISK. 



been figured, so it seems worth while to illustrate its principal features 

 here. The specimen before me has three tentacle scales on each of the 

 basal arm pores, but this is not characteristic of the species. 



OPHIOCOMA BREVIPES. 



0-phiocoma hrevipes Peters, Arch. f. Naturg., vol. 18 (1), 1852, p. 85. 



Locality. — Tanegashima, Japan, 1906, 6 specimens. 



The disk diameter of these individuals ranges from 8 to 27 mm. 

 The smallest has some white markings near the disk margin but the 

 others are uniformly blackish above. 



