SEA LILIES, STARFISHES, ETC.—CLARK. 37 
apparently about 2 mm. Breadth at proximal margin of 
first superomarginals which meet=length of first three supero- 
marginals (counting from interradius). Disk flat, rather 
large ; rays moderately long and quite narrow, all broken at 
tip, but one seems to be nearly complete, quadrangular in 
cross-section with very slightly rounded angles, the width 
slightly exceeding the thickness, at all points. Abactinal 
plates entirely confined to disk, forming an almost perfectly 
pentagonal area, the sides of which are so slightly concave 
as to appear almost straight ; there are 650-700 plates in this 
area but most of these are very small and lie along the 
boundaries formed by the superomarginal plates; the largest 
abactinal plates are near the centre of the disk in the inter- 
radii and along the midradial lines. At the centre of the 
disk and in the radial areas where the papule occur, the 
plates are more or less stellate or substellate basally, the upper 
surface being rounded pentagonal or subcircular ; each plate 
carries 15-25 coarse granules, nearly spherical and not at all 
rough, those of the marginal circle not being appreciably 
different from the rest ; near the superomarginal plates, the 
abactinal plates are so small and crowded, the granules tend 
to form a continuous coat with those on the superomarginals. 
The latter are apparently rather more than 20 on each side 
of each ray, and excepting the basal 4 pairs are in complete 
contact in the midradial line ; they are very flat, not at all 
tumid, and in the interbrachial arcs overhang the infero- 
marginals ; eight superomarginals make up each side of the 
disk-pentagon ; they are wider than long, the middle pair 
being each 5 mm. wide by 2.5 mm. long ; at the middle of the 
arm the superomarginals are each about 2 mm. long, 2 mm. 
wide, and 1.5 mm. thick ; all the superomarginals are covered 
by a uniform coating of granules similar to those on the 
abactinal plates ; these are largely rubbed off in the present 
specimen ; on the entire surface of each of the middle pair of 
superomarginals, there are about 200 granules. 
Inferomarginals coincide in number and position with the 
superomarginals (except when regeneration has occurred), but 
owing to the presence of the ambulacral groove they are much 
narrower ; at the middle of the arm they are about 2 mm. long, 
1mm. wide and | mm. thick; like the superomarginals, they are 
clothed with a close coat of granules, each one of the middle 
pair carrying about 150. Actinal intermediate plates wanting 
on rays; the series adjoining the adambulacral plates, extends 
only to the fourth inferomarginal and contains 10-12 plates ; 
outside of it is a series of 6-8 plates, then a series of 5-6, then 
