MONOGRAPH OP JAPANESE OPHIUROIDEA. 131 



Eastern Sea; 3G1-440 fathoms (Clauk). Bungo Channel; 720 

 fathoms (Clark). Ofl" Shio Misaki ; 587 fathoms (Clabk). Off 

 Omai Zaki ; 624 fathoms (Clark). 



Key to Japanese species of OpUiomitra, 



A — Disk scales coarse; radial shields very narrow, widely separated 

 from each other ; oral shields rhomboidal or pentagonal, abont as 

 wide as long ; five or six arm spines, of Avhich the uppermost or 

 the next one is the longest and al>out twice as long as the cor- 

 responding arm joint hytJdaspis. 



^^— Disk scales fine ; radial shields not very wide, lying rather closely 

 side by side ; oral shields much wider than long ; six or seven 

 arm spines, of which the uppermost or the next one is the longest 

 and about tlnice as long as the corresponding arm pint , Jifhosora. 



OpJiioniitrn hythiaspis Clark. 



OpMomitra hythiaspis : Clark, Bull. U. 8. Nat. Mus., LXXV, 1911, p 

 185, fig. 58. 



Off Yenshii Sea ; 043 fathoms (CJlark). 



OpJiiomitra lithosora (Clark). 



OpUocamax lithosora : Clark, Bull. U. S. Nat. Mus., LXXV, 1911, p. 

 191, fig. 89. 



Off Kii ; 244-253 fathoms (Clark). Eastern Sea ; 361 fathoms 

 (Clark). 



In the genuine OpUocamax, the disk is not very deeply lobed 

 and the radial shields are joined in pairs along the whole length. 

 The present species lacks these characteristics of Ophlocamax, but 

 exhibits all the characteristics of Ophiomitra as emended by 

 Verrill, 1899. 



