JAPANESE ASTEEOIDEA. 339 



pronouncedly convex outer surface, and in the specimen before 

 me the plates are never perfectly coincident with the inferomarginals, 

 oven at the interradial line. Along the larger part of the arms 

 the two series are strictly alternate. At the interradial line the 

 plates are nearly as high as long, but less than half as wide 

 (PI. XII, fig. 184). In the arms the width increases in comparison 

 to the height and length, but the general quadrate form is 

 maintained on a marginal view. Each plate is margined with a 

 single row of closely arranged, small granules of a cubical form, 

 and the entire surface bears numerous spherical granules of 

 various size, which are well separated from one another. When 

 these granules are detached, which can be done with comparative 

 ease, there is seen in the place of each a hollow pit in which 

 the granule was lodged. There are, besides, a few (usually one 

 to four) valvate podicellariaG of various sizes, exactly similar 

 in form to those of the abactinal plates. These pedicellarise also 

 lie in excavations of the plates. The fasciolar grooves appear to 

 be totally absent, the plates being closely contiguous. Eelatively 

 to the size of the body the superomarginals are few, there being 

 13 or 14 on either side of the interradial line. Each superomar- 

 ginal plate presents a more or less convex border towards the 

 paxillar area. 



Inferomarginals. — The inferomarginals are closely similar to 

 the superomarginals in all respects. At the interradial line each 

 plate is slightly broader than long, and the plates lie well on the 

 actinal side, so that we can not speak of their height. At the 

 base of the arms, however, the plates are as high as long and 

 only half as wide, while near the tip the height is usually greater 

 than the length and the width is about half as great as the 



