492 s. GOiX): 



bulacral spines in form, and are, like them, longitudinally grooved 

 in the terminal parts. 



Ventrolaterals. — The ventrolateral plates themselves are com- 

 pleteh^ hidden from view ])y the coarse granulation that covers 

 them, but the granules are arranged into groups correspond- 

 ing to the underlying plates, so that their arrangement and 

 general form can be inferred. It appears that the ventrolateral 

 plates are of comparatively small size and have no regular ar- 

 rangement, except along either side of the arabulacral furrow, 

 where the plates appear to form a single regular row. The plates 

 are covered over with large, polygonal, flattened granules, and the 

 spaces between the plates are covered with smaller granules. 

 Between the large granules covering the plates are seen many 

 transversely elongated valvate pedicellarite, which are more nume- 

 rous on either side of the ambulacral furrows and in the angles 

 of the mouth. On some of the plat3s there may be two or more 

 of these pedicellariae, but there are also many plates destitute of 

 them (PI. XIV, fig. 224, 227). 



Ahactinal plates. — The most conspicuous feature of the abac- 

 tinal side is the presence of conical tubercles along the lophial line. 

 In my specimen there are eight or nine of these for each arm, of 

 which the most central one, the apical, is especially large, and with 

 their fellows enclose a central space at the summit of the disk, 

 within which there are, in my specimen, two tubercles of nearly 

 the same size as those at the base of the arms. Moreover there 

 is a tubercle on either side of the one next the apical tubercle, 

 and a similar pair for the next lophial tubercle at a greater dis- 

 tance from the latter, so that there are, in each interradius, two 

 pairs of accessory tubercles. In some interradii, however, this 



