82 BULLETIN 75, UNITED STATES NATIONAL MUSEUM. 



on distal; after about the seventh pore, there are no scales on distal 

 side, though there may still be six on the proximal; on terminal part of 

 arm there are three or two scales on the proximal side only. Color 

 (dried from alcohol), dirty-whitish or ivory white. 



Localities. Albatross, station 2860, off Washington, lat. 51 23' N.; 

 long. 130 34' W., 876 fathoms, green mud, bottom temperature 36.5, 

 11 specimens; station 3074, off Washington, lat. 47 22' N.; long. 

 125 48' 30" W., 877 fathoms, green mud, bottom temperature 36.6, 

 1 specimen; station 3075, off Washington, lat. 47 22' N. ; long. 

 125 41' W., 859 fathoms, green mud, bottom temperature 36.6, 

 6 specimens. Bathymetrical range, 859 to 877 fathoms. Tempera- 

 ture range, 36.6 to 36.5. Eighteen specimens. 



Type. Cat. No. 25612, U.S.N.M., from station 3075. 



This handsome species is a near relative of ponderosa, but is at once 

 distinguished from that species by the rounded arms, with very 

 different arm spines. It is evidently an inhabitant of deeper, colder 

 water, and apparently has a much more restricted range. The speci- 

 mens from station 2860 are all small, with disk diameters ranging 

 from 3.5 to 9 mm.; the largest has two arms nearly unbroken, only 

 the tip is gone, and these are about 30 mm. long. These young 

 specimens resemble the adults in all essential particulars, except in 

 the number of arm spines; most of them have only a single spine, but 

 the larger ones have two well-spaced spines on most of the basal 

 joints. In the adults from stations 3074 and 3075, the arms are all 

 broken in their basal half, so it is not possible to determine the num- 

 ber of arm spines near their tips. 



OPHIURA STIPHRA, new species, a. 



Disk 16 mm. in diameter; arms about 42 mm. long. Disk high, 

 about 7 mm. thick, covered by a smooth, firm coat, of about one 

 hundred and twenty-five scales, among which the primary plates can 

 be distinguished but the radial shields are the most prominent. 

 Radial shields about as wide as long, in contact near middle but sepa- 

 rated within and widely so distally, by a single large scale. Arms 

 high at base, distinctly compressed. Upper arm plates rather variable 

 in shape, but tending to be more or less distinctly hexagonal, though 

 basal ones have decidedly convex distal margins; basal ones also 

 much witler than long but beyond middle of arm, length generally 

 exceeds width. Interbrachial spaces below, each nearly one-half 

 covered by oral shield, distal to which is a series of about four long 

 plates, which occupy most of remaining space. Oral shield oval, 

 narrower proximally. Adoral plates nearly triangular, pointed dis- 

 tally, but with very indistinct outlines; oral plates narrow but con- 

 spicuously swollen at proximal end, so that there is a marked eleva- 



aS-ct<j>pb, signifying compact, solid, in reference to the hard, compact structure. 



