170 



ECHIN0DERM8 OF THE BRITISH ISLES 



In British seas this species has been found only in the cold 

 area of the Faroe Channel ca. 500-1100 m. ("Porcupine", 

 ''Mich. Sars "). It is elsewhere distributed from Skagerrack to 

 Sj3itzbergen, and from Greenland to 38° N. on the American 

 coast. Bathymetrical distribution ca. 50-1900 m. 



2. 0])hioscolex purpureus Diiben and Koren. (Fig. 95, a, c, and d.) 



Disk with scattered, small spines (often distinct only on drying 

 the specimens). Dorsal plates of arms rather well developed, 



Fig. 95.- 



-Ophioscolex glacialis {b and e) and O. purpureus (a, c, and d). 

 (After Th. Mortensen, Scand. Echinod.) 



6. 



a and b, Part of oral side ; d and e, Dorsal side of arm, proximal part, with adjoining 

 part of disk ; c, Part of arm of 0. purpureus, near the end, in side view ; shows the spines 

 transformed into hooks. 



covering the whole dorsal side of arms so that the vertebrae are 

 not seen ; proximally they are rather irregular, farther out more 

 regular, two to each segment (Fig. 95, d). Ventral plates in the 

 main as in glacialis. Mouth shields broad, low ; adoral shields 

 without spine. Arm spines 3, fairly thick, smooth ; in the distal 

 part of arm the two upper spines are transformed into hooks. One 

 slender tentacle scale. Six to ten mouth papillae on each side of 

 jaw. Colour as in glacialis. Appears not to reach quite as large 

 a size as that species. 



Judging from an interesting observation by Grieg it would 



