JAPANESE ASTEEOIDEA. 



333 



when killed. The abactinal side is prominently convex and the in- 

 terradial areas are depressed, so that the dorsal surface is more 

 or less pyramidal in shape ^Yith indented bases. The actinal side 

 of the disk is distinctly concave, and there is a radiating depres- 

 sion in each interradius. I have only one specimen of which 

 the measurements are as follows : 



Siiperomarjinals. — The superomarginal plates are very well 

 developed and are nearly of the same rectangular form up to near 

 the tip of the arms. At the interradial angle they are twice as 

 broad as long, but become less broad towards the tip of the arms. 

 The surface is completely covered over with coarse, well spaced 

 granules of a polygonal or roundish shape, which are slightly 

 smaller near the inner edge of the plates. Many of the plates bear 

 one or two va Iva te pedicellariœ similar to the smaller ones found 

 on the paxillae, and usually surrounded by an empty space, 

 making them the more conspicuous. 



Inferomargincds. — The inferomarginal plates are also very 

 well developed and similar in general shape to the supero- 

 marginals, but mostly a little longer, so that they are contingent 

 with the superomarginals only for one or two plates on either 

 side of the interradial line and more or less alternate for the 

 rest of the arms. The granules covering the entire surface are 

 similar to those of the superomarginals, and some of the plates 

 bear near their outer border a transversely elongated vice- shaped 

 pedicellarige, which are usually larger than those of the supero- 



