MONOGRAPH OF JAPANESE OPHIUEOIDEA. 



241 



the disk proper, or of the circle passing through the outer 

 ends of the radial shields, 7 ram. Length of the free portion 

 of the arms 6 mm. Width of same near the pentagonal body 

 0.4 mm. 



The pentagonal " asteroid " body is very flat, covered entire- 

 ly by the stout primary plates and radial shields of the disk 

 proper and by the dorsal 

 and lateral arm plates of 

 the modified basal portion 

 of the arms. The primary 

 plates are the central, the 

 five infrabasals, five basais, 

 five radiais and five first 

 and five second inter- 

 radials. The infrabasals, 

 basais and interradiais are 

 elevated above the level 

 of the central, radiais and 

 radial shields, so as to 

 form a regular symmetric- 

 al system of ridges. The 

 central plate is ten- sided, 

 the sides corresponding to 



the infrabasals being longer than those corresponding to the 

 basais. Infrabasals small, rectangular, wider than long. Basais 

 pentagonal, with truncated inner angle, wliich abuts on the central 

 plate, lateral edges concave corresponding to the radiais, much 

 longer than wide. First interradiais rectangular, with concave 

 lateral edges corresponding to the radial shields, much longer than 

 wide. Second interradiais large, pentagonal, with short and 



Fig. 68. Astrophiura kmcamnrai x6. 

 fibove. b. From below. 



a. From 



