870 s. GOTO : 



lateral plates. Besides, there are some ten or a dozen spines 

 between the rows of the ambulacral sides, of which the more 

 distal are short and blunt, while the more proximal ones (i.e. 

 those nearer the month) are longer and just Hke those of the 

 ambulacral border. 



Ventrolaterals. — The ventrolateral plates are mostly lozenge- 

 shaped and are fast ankylosed with one another ; in a specimen 

 of R— 40 mm., there are as many as seventy ventrolaterals in 

 one interradius, including those in the arms. A single row of 

 these plates can be followed out as far as two-thirds of the 

 length of each arm. The ventrolaterals are covered with short, 

 truncated spines, of which as many as fifteen may be borne by a 

 single larger plate. 



Paxillœ. — The paxilloe are closely set and are smallest around 

 the centre of the disk ; this central area is not, however, so con- 

 spicuous as in Astropecten. The coronal spinelets belonging to each 

 paxilla are marked off into polygonal groups by mutual pressure. 

 The centrals and peripherals are very distinct from each other, 

 the latter being considerably smaller. On one of the largest paxillaß, 

 which are usually found about the middle of the base of the arms, 

 there may be as many as fifteen centrals and some twenty-three 

 or more peripherals (PI. VIII, fig. 134). Both the centrals and peri- 

 pherals are very short, although the latter are a little longer and 

 more slender. In denuded specimens the paxillar tabula are seen 

 to form regular longitudinal rows in the proximal half of the 

 arms, but are somewhat more irregularly arranged in the 

 distal half (PI. VIÏI, fig. 129). The surface of the tabula are 

 mostly circular or slightly elliptical, and their bases are fast 

 ankylosed. The papular pores are uniformly distributed on the 



