NORTH PACIFIC OPHIURANS IN NATIONAL MUSEUM CLARK. 247 



brachial spaces below covered by coarse scales. Genital slits large. 

 Oral shields rhombic, wider than long. Adoral plates thick, about 

 twice as long as wide; oral plates small. Oral papillae, three on a 

 side and one at apex, thick and blunt, outermost largest. Under 

 arm plates tetragonal, much wider than long, the distal margin with 

 more or less of a median notch; well separated from each other. 

 Side arm plates large and somewhat swollen, meeting above and 

 below. Each plate carries four short, thick, smooth arm spines, of 

 which the uppermost or next lower is the longest, and hardly exceeds 

 a joint. Tentacle pores minute or wanting; tentacle scale single, 

 large, thick, rounded or bluntly pointed. Color (dried from alcohol), 

 yellowish-brown. 



Localities Albatross station 2858, off Alaska, lat. 58 17' N.; long. 

 148 36' W., 230 fathoms, blue mud, gravel, bottom temperature 

 39.8, 2 specimens; station 3480, Bering Sea, lat. 52 6' K; long. 

 171 45' W., 283 fathoms, black sand, coral, rocky, 26 specimens; 

 station 4781, off Agattu Island, lat. 52 14' 30" N.; long. 174 13' 

 E., 482 fathoms, fine gray sand, pebbles, bottom temperature 38.6, 

 2 specimens. 



Type.C&t. No. 25620, U.S.N.M., from station 3480. 



There is an excellent series of this species, showing a range in disk 

 diameter from 4 to 10 mm. All the specimens agree in number and 

 character of arm spines, so that this may well be considered the 

 distinguishing mark of the species. Small specimens of diapTiora, 

 with only four or five arm spines, are hard to separate from pau- 

 cispina, though the thicker granulation of the disk and the shape 

 of the under arm plates will usually distinguish them. The adults 

 can not be confused. 



OPHIOLEBES BREVISPINA, new species, a 



Disk 8 mm. in diameter; arms about 20 mm. long. Disk covered 

 with thick, irregular, overlapping scales, showing no very definite 

 arrangement and without granules or spines. Radial shields moder- 

 ate, rounded, widely separated. Upper arm plates rounded, swollen, 

 much wider than long, nearly or quite in contact on basal half of arm. 

 Interbrachial spaces below, covered by thick scales. Genital slits 

 short. Oral shields rhombic or pentagonal, about as long as wide. 

 Adoral plates short and very wide, with inner ends rounded; oral 

 plates large. Oral papillse three on a side and one at apex of jaw, 

 rounded or pointed at tip, outermost largest. Under arm plates 

 tetragonal or pentagonal, wider than long, all but first two widely 

 separated from each other. Side arm plates large, more or less 

 swollen, meeting below and nearly or quite meeting above; each plate 



o Brevis, signifying short, and spinus, signifying a spine, in reference to the very short 

 arm spines. 



