NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 65 



outermost widest; an unpaired infradental papilla is often present. 

 Genital slits rather short. Genital scales large, broad distally, but 

 completely overshadowed by radial shields, so that they are not visible 

 from above; each scale carries a few irregular marginal papillae but 

 these are so imperfectly developed that there is no arm comb in any 

 of the specimens; some small, irregular scales just distal to the radial 

 shields give the superficial appearance of a comb in some cases, but 

 these have no connection with the genital scales. First under arm 

 plate rounded triangular; succeeding plates pentagonal, soon becom- 

 ing triangular; all are much wider than long, and are distinctly sepa- 

 rated from each other. Side arm plates large, meeting broadly both 

 above and below; each plate carries four minute arm spines, one of 

 which is high up on the plate, well separated from the other three, 

 which are very low down and close together; the middle one of these 

 three is usually the longest spine but scarcely equals half the joint; 

 the lowest one might easily be mistaken for a tentacle scale. Tentacle 

 pores on arm minute and confined to the three or four basal joints; 

 each one is protected by several minute scales. Oral pore not open- 

 ing into mouth slit, protected by three or four rounded scales on each 

 side. Color (dried from alcohol) ; scales and plates above clay color 

 or brown, the skin between them decidedly darker; beneath, uniform 

 dirty whitish, or brown. 



Localities. Albatross station 4980, off eastern Japan, lat. 34 9' N.; 

 long. 137 55' E., 507 fathoms, brown mud, fine sand, foraminifera, 

 bottom temperature 39, 4 specimens; station 5083, off Oinai Saki 

 light, lat. 34 4' '20" X.; long. 137 57' 30" E., 624 fathoms, fine 

 gray sand, globigerina, bottom temperature 38.1, 16 specimens; 

 station 5084, off Omai Saki light, lat. 34 N.; long. 137 49' 40" E., 

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

 36.8, 2 specimens. Bathymetrical range, 507 to 91 X fathoms. 

 Temperature range, 39 to 36 8'. Twenty-two specimens. 



Type. Cat. No. 25547, U.S.N.M., from station 5084. 



Although this species bears some resemblance dorsally to Opldo- 

 glypha divisa Liitken and Mortensen, the oral side is so different there 

 can be no confusion between the two. I do not think there is any 

 other species more nearly related to this Japanese novelt}*, unless it 

 be 0. confragosa Lyman, from off La Plata, but the upper arm plates 

 of the latter are alone sufficient to distinguish the two. 



OPHIURA MONOSTCECHA, new species.a 



Disk 10 mm. in diameter; arms about 35 mm. long. Disk covered 

 with a smooth coat of scales, among which the six primary plates, 

 another plate in each radius, and two in each iriterradius, one of 



a Mbvos, signifying one, single, and a-co'egoe, signifying a row, line, in reference to the 

 peculiar arm comb. 



34916 Bull. 7511 5 



