128 OPHITJEOIDEA. 



2. Ophiacantha spectabilis. 



Ophiacantha spectabilis, G. O. Sars, Foih. Vid.-Selslc, Christ. 1871 

 (1872), p. 10 ; Lyman, Chall. Rep. Oph. (1882) p. 198 ; Hoyle, Proc. 

 R. Soc. Ed, xii. (1884) p. 714. 



A rather large species. Disk pretty thickly covered with more 

 or less short spines. Arm- spines smooth, seven or eight in number, 

 radiating in all directions, and some as much as 5 mm. long ; the 

 uppermost have sharp, the lower blunt ends. Mouth-papillae from 

 four to eight ; mouth-shields rounded triangular, wider than long ; 

 side mouth-plates rather large. A single tentacle-scale on all but 

 the most distal joints, where there may be two. Diameter of disk 

 14 mm. : R is said to be =4r. 



Colour, in spirit, whitish ; " uniformiter fulvus vel castaneus, 

 nullas maculas vel fascias obscuriores ostendens " (Sars). 



Reported by Hoyle from the Faeroe Channel. 



Distribution. Norway; 80-433 fms. 



3. Ophiacantha abyssicola. 



Ophiacantha abvssicola, G. O. Sars, Fork. Vid.-Selsh. Christ. 1871 

 (1872), p. 8; Lyman, Chall. Rep. Oph. (1882) p. 199; Hoyle, 

 Proc. R. Soc. Ed. xii. (1884) pp. 711-713. 



A small species, with the arm-joints so constricted as to give them 

 a knotted appearance. Disk almost smooth. Arm-spines smooth, 

 seven near base, fewer more distally, the longest the uppermost, 

 gradually but considerably diminishing in size to the lowermost ; the 

 longest as much as 2 mm. The arms most remarkable for their 

 moniliform appearance, each arm-joint being much wider along 

 its distal than its proximal edge. Three or four mouth-papilla? 

 very prominent and distinct. Mouth-shield constricted in its outer 

 half by the invasion of the bursal slits. A single tentacle-scale. 

 Diameter of disk 9 mm. R is said to be = 10 r. 



Colour, in spirit, white ; " uniformiter pallide ferrugineus, brachiis 

 interdum fasciis obscurioribus transversis indistincte ornatis" (Sars). 



Distribution. Northern parts of East Atlantic, and Arctic Circle. 

 20-312 fms. 



a, b. Faeroe Channel, 312 fms. ' Porcupine ' Exp. (St. 82). 



c-f. Faeroe Channel, 290 fms. < Porcupine ' Exp. (St. 78). 



OPHIOCOMID^ (see p. 26). 



1. 0PHI0C0MA. 



Ophiocoma, Ag. Mem. Soc. Neuchdt. i. (1836) p. 192 ; M. Tr. Syst. 

 Ast. (1842) p. 98 ; Lyman, III. Cat. M. C. Z. i. (1865) p. 70 ; Norm. 

 Ann. 8f Mag. xv. (1865) p. Ill ; Lyman, Chall. Rep. Oph, (1882) 

 p. 167. 



