MONOGEAPH OF JArANESE OPHIÜROIDEA. 



331 



whicli the six primaries are somewhat distinct. Central plate 

 rather large, circular, conspicuous. Radiais smaller and less con- 

 spicuous than the central plate, separated from one another and 

 from the central plate. liadial shields triangular, with acute inner 



Fig. 92. Ophloplax lamellossa. x 16. a. From above, h. From below. 

 c. Side view of three arm joints near disk. 



angle, twice as long as wide, those of a pair widely separated 

 from each other. Interbrachial ventral surfaces entirely covered 

 with very fine granules. Genital slits very large, reaching to the 

 margin of the disk. 



Oral shields large, triangular, with strongly curved outer 

 border, less curved lateral sides, obtuse inner angle, and perfectly 

 rounded lateral angles ; longer than wide. Adorai shields also 



