MONOGRAPH OF JAPANESE OPRIUROIDEA. 



127 



Diameter of disk 3 mm. Lengtli of arms 23 mm. Width of 

 arms at base 0.5 mm. 



Disk five-lobed, i.e. divided by five radiating interradial 

 f arrows into five heart-shaped lobes, with large radial shields and 



Fig. 32. Ophiothamnus venustus. x20. a. From above, h. From below. 

 c. Side view of three arm joints near disk. 



