JAPANESE ASTEEOIDEA. 357 



one next the ämbulacral furrow is largest and similar to the last 

 spine of the first mentioned row, the other spines gradually be- 

 coming shorter towards the abcentral end of the mouth-plate. 

 On the actinal surface of the mouth -plate there is a somewhat 

 irregular row of three to five spines along the suture line of the 

 plate, of which the one nearest the mouth is largest. There is an 

 unarmed space left between this spine and the first mentioned 

 row of spines. In the smaller specimen the spines along the 

 suture line form a more regular series (PI. IX, fig. 147). 



Ventrolaterals. — These are very numerous and extend far 

 out into the arms, a single row (the innermost) reaching as far 

 as the fourteenth inferomarginal plate as counted from the apex 

 of the arms. The larger ones bear as many as ten spines, 

 which are tolerably long and distinctly pyramidal in form. Some- 

 times there are many peripherals and one or two centrals, 

 simulating the appearance of paxilloe. An interesting point is 

 that some of the venti-olaterals bear pedicellariEe, which are different 

 in form from those of the aboral side or the inferomarginal s and 

 are mostly 3-valvate, but occasionally 4-valvate (PL IX, fig. 149, 

 150). In denuded parts their positions are marked by a pore 

 in the plate. These pedicellarise are interesting as having a very 

 primitive form, and can be detected only on careful examina- 

 tion. They appear to be even more primitive than those found 

 on the paxillse or the inferomarginals. 



Paxillœ. — The paxillœ are fairly large, and the top of the 

 tabulum is either circular or elhptical. Those at the centre of 

 the disk are hardly smaller than the others. Those far out in the 

 arms are small, the largest ones being found along the elevated 

 radial zones meetincr in the centre of the disk. Thus there is 



