OPHIUROIDEA 193 



in alcohol dark brown. A rather robust species reaching a size 

 of at least 12 mm. diameter of disk. Length of arms ca. 4 times 

 diameter of disk. 



In British seas this species has been found off S.W. Ireland, in 



Fig. 106. — Ophiacantha crassidens ; part of oral side. (After Far ran, 

 Deep-Water Ast. . . . Ireland.) x ca. 6. 



ca. 970-1770 m. (" Helga "). It is elsewhere known from off the 

 Azores (" Princesse AUce "), from 45° 26' N., 25° 45' W., 3120 m. 

 (" Michael Sars "), and from off Cape Hatteras, N.E. America. 

 Bathymetrical distribution ca. 970-3120 m. 



3. Ophiacantha aristata Koehler. (Fig. 107.) 



Disk covered with rather coarse stumps ending in a crown of 

 7-8 spines, which may be arranged so as to form a cross. Scales 



Fig. 107. — Ophiacantha aristata ; part of oral side. (After Farran, 

 Deep-Water Ast. . . . Ireland.) x ca. 6. 



of disk and radial shields not distinct. Dorsal arm plates very 

 small, triangular with convex outer edge, widely separated even 



o 



