338 



ABT. 2. — H. MATSUMOTO : 



Ophiocrasis marktanneri Matsumoto. 

 OpUonereis porreda : Marktanner-Tüeneretschee, Ann. K. K. Naturli. 

 Hofmus., II, 1887, p. 302, PL Xn, fig. 18. (Non Lyman, 1860.) 



' OpUonereis porreda Marktanner ': Kœhler, Bull. Sei. Fr. Belg., 

 XXXI, 1898, p. 76. 



Ophiocrasis marManneri : Matsumoto, Proc. Acad. Nat. Sei. Philadel- 

 phia, 1915, p. 90. 



Three specimens ; Enoshima, Sagami. Numerous specimens ; 

 Arai Beach, Misaki Marine Biological Station. 



Diameter of disk 9 mm. Length of arms 68 mm. Width of 

 arms at base 1.2 mm.; at the widest part 1.5 mm. 



Disk circular, slightly convex, rather soft, covered with 



very fine, imbricating 

 scales, which are rather 

 obscured, so that the 

 disk appears as if 

 covered by a thick 

 skin. Radial shields 

 very small, short and 

 exceedingly narrow, 

 tapered within, those 

 of a pair widely 

 separated from each 

 other, also rather 

 obscure. Interbrachial 

 ventral surfaces cover- 

 ed with scales similar 

 to those of the dorsal 

 side, but even more 

 obscure. Genital slits large, nearly reaching to the border of the 

 disk. No genital papillae. 



Fig. 94. Ophiocrasis marktanneri. x7. a. From above. 

 h. From below, c. Side view of three arm joints near 

 disk. 



