134 OPHIUROIDEA. 
STREPTOPHIURG (see p. 26). 
1. OPHIOSCOLEX. 
Ophioscolex, WM. Tr. Syst. Ast. (1842) p. 109; Lyman, Chall. Lep. 
Oph. (1882) p. 252. 
Teeth and mouth-papille; tooth-papille present or absent. 
No upper arm-plates. A thick naked skin covers all the disk and 
extends on to the arms and spines. ‘Tentacle-scales present or 
absent. 
Key to the Species. 
Mouth-papille seven to ten ...:.-......225 1. O. glacials. 
Mouth-papille tem or more ..0........:..-- 2. O. purpurea. 
1. Ophioscolex glacialis. 
Ophioscolex glacialis, M. Tr. Syst. Ast. (1842) p. 109; Barr. § 
M‘ Andrew, Ann. § Mag. xx. (1857) p.46; Sars, Norg. Ech. (1861) 
pp-7&12; Lyman, Bull. M. C. Z. x. (1883) p. 268; Hoyle, Proc. 
Kk. Soe. Edinb. xii. (1884) p. 720. 
Disk nearly circular; arms seven to nine times as long as radius 
of disk, flattened, tapering rather rapidly. All the parts of the disk 
are obscured by the thick wrinkled skin, except the seven to ten 
somewhat irregularly arranged delicate mouth-papille. Three deli- 
cate arm-spines about as long as the arm is broad. No tentacle- 
scale. 
Colour, in spirit, yellowish white. 
R=65; 42. r=7; 
6. 
Distribution. Both sides of North Atlantic, as far south as 
38° 21' 50” N., 73° 32’ W. (West Indies?) on the west, from 
Faeroe to Spitzbergen on the east. 100-300 fms, 
Some semi-macerated fragments, determined by Mr. Lyman, from 
60° 0’ N., 5° 13’ W., 312 fms. * Porcupine’ Exp. 
2. Ophioscolex purpurea. 
Ophioscolex purpurea, Diib. § Kor. Vet.-Akad. Hdlg. 1844 (1846), 
p. 235, pl. vi. fig. 2; Sars, Nory. Ech. (1861) p. 8. 
Ophioscolex purpureus, Lyman, Bull. C. M. Z, v. (1878) p. 233 ad. 
Chall. Rep. Oph. (1882) p. 234; Hoyle, Proc. Roy. Soc. Ed. xii. 
(1884) p. 720. 
Disk pentangular; arms about cight times as long as the radius 
of the disk, flattened, do not taper very rapidly. Mouth-papille 
more numerous (ten or more), stouter, and more regularly arranged 
