JAPANESE ASTEEOIDEA. 211 



less slender and long. From the general armature of the infero- 

 marginals a somewhat irregular series of long conspicuous spines 

 distinguish themselves ; it consists of 5-9 spines, runs usually 

 obliquely from the outer proximal corner of the plate towards the 

 diagonally opposite corner, the spines being particularly crowded 

 along the margin of the arm, where they form a conspicuous 

 feature when viewed from the side. They are not, however, so 

 conspicuous in an oral or aboral view of the animal, since 

 the spines near the margin are usually adpressed to the plates. 

 The outermost of these conspicuous spines is very close to the 

 aboral margin of the plate, and in a lateral view of the arm the 

 conspicuous spines of the two marginals are seen to form a 

 continuous series. Besides the series of conspicuous spines 

 above mentioned, a few additional spines of conspicuous 

 length may be present on each inferomarginal. The trans- 

 verse grooves between the inferomarginals are covered with 

 capillary spinelets. 



Adamhulacml 2:)lates. — In the greater part of the arms, there 

 are 6 adambulacrals to 5 of the inferomarginals. In denuded 

 specimens, the first 4-5 plates are rounded towards the ambulacral 

 furrow, but the rest present a rather sharp wedge-shaped edge 

 on this side, the edge becoming in general more acutely angled 

 towards the tip of the arms. Along this edge is a regularly curved 

 row of 5-7 tubercles supporting the ambulacral spines, and on the 

 remaining actinal surface of the plate there are some ten or 

 twelve tubercles, each supporting a spine (Pi. II, fig. 27). The 

 furrow spines are very long, and usaally flattened, with the sharp 

 edge turned towards the furrow (PL II, fig. 26). The spines on 

 the actinal surface of the plate are frequently furrowed longitudinally. 



