84 GONIASTERIDAE. 
4-12 plates, noticeably larger than the others, and among these are the only 
papulae to be found, but even these are small and inconspicuous. All the 
abactinal plates are surrounded by a series of small rounded granules; on the 
disk, the surface of each plate also carries several (3-15) similar granules; these 
may be crowded but are usually rather well-spaced. On the arms, the granules 
on the surface of the plates become few and disappear, so that at the tips of the 
arms, the plates entirely lack them, only the marginal series being present there. 
Marginal plates 15 on each side of each ray, or 16 in the inferomarginal 
series; the plates in the two series are of about equal size or the inferomarginals 
are somewhat larger than the superomarginals in the interbrachial are and 
somewhat smaller at the very tip of the ray. Distally each plate is surrounded 
by a marginal series of small granules, like those of the abactinal plates, while 
the surface of the plate is bare, but as one passes towards the interradius, granules 
appear on the surface and in the interbrachial are pretty well cover the plates; 
those on the inferomarginals are larger than those on the upper series and are 
quite angular and more or less pointed. Terminal plate slightly tumid, smooth, 
transversely oval, not conspicuous. 
Actinolateral plates squarish or polygonal not arranged in very definite 
series, except one row adjacent to the adambulacrals; the plates of this row are 
the largest and proximally are more than a millimeter square. They extend 
out two thirds the length of the arm, beyond which the adambulacrals abut 
directly on the inferomarginals. All the actinolateral plates are moderately 
well-covered with spaced, pointed spinelets, considerably larger than the granules 
of the abactinal surface. Adambulacral plates squarish, proximally about 
equal to the adjoining actinolaterals but becoming larger (relatively only, of 
course) at middle of arm. Each plate bears a marginal series of five or usually 
four subequal, slightly tapered blunt spines, about a millimeter long; im- 
mediately external to this marginal series, the surface of the plate is bare, but 
along the outer margin are 4-8 pointed granules or low spinelets similar to those 
of the actinolateral plates, but perhaps a little larger; these are arranged in 
one or often two distinct series. Oral plates large but not very tumid; each 
carries a marginal series of 10-12 spines similar to those of the adambulacral 
plates, except that the one at the tip of plate (proximally) is noticeably stouter 
than the others; on the surface of the plate are 10-14 low spinelets like those of 
the actinolateral plates but a little larger. 
Pedicellariae are exceedingly rare but on each specimen critically examined, 
one was found; this was composed of two wide, blunt, erect valves, slightly 
