MONOGRAPH OF JAPANESE OPHIÜROIDEA. 201 



Atnphiura trachydisca Clark. 



AmpMura trachydisca : Clark, Bull. U. S. Nat. Mus., LXXV, 1911, p. 

 149, fig. 60. 



One specimen ; Yahagi-gaké, Sagami Sea ; 310 fathoms. 

 Two specimens ; Nakano-yodomi, Sagami Sea ; 210 fathoms. 

 Numerous specimens; Okinosé, Sagami Sea; 100 fathoms. 

 Numerous specimens ; Sagami Sea. 



Off Heda; 161-167 fathoms (Clark). Suruga Gulf; 108-148 

 fathoms (Claek). Uraga Channel ; 88 fathoms (Clark). 



The largest one of these specimens is 15 mm. across the disk. 

 Those from Okinosé are somewhat different from the other speci- 

 mens, which agree quite well with Clark's type, and have an 

 almost smooth disk and relatively narrower arms, though there is 

 no doubt that they belong to this species. 



Amj^hiura microdiscus Duncan. 



Hemipholis microdiscus : Duncan, Journ. Linn. Soc. London, XIV, 1879, 

 p. 467, PL X, figs. 20-22 ; Lyman, Rep. Challenger, V, 1882, p. 158. 



Korea Strait ; 51 fathoms (Duncan). 



According to Duncan, this species has two pairs of oral 

 papillaß to each oral angle, the apical ones being infradental and 

 the distal ones arising from the adorai shields. There is therefore 

 no doubt that, this species is a genuine Amphiura and not a 

 Hemipholis. 



Amphiura eiiopla Clark. 



Ampliiura Candida : Marktanner-Turneretscher, Ami. K. K. Naturh. 

 Hofmus, II, 1887, p. 299. (Non Ltungman, 1866.) 



