F. B. Meek—Deseriptons of new Silurian Fossils. 275 
Breadth of disk, about 0:48 inch; breadth of arms at their 
0 inch. 
belong to this species is very imperfect, being merely an incom- 
plete disk, and the inner ends of the rays. It does not con- 
po &, 18 Covered by an integument composed of a vast num 
Ol very minute grains of calcareous matter, instead of distinct 
establishment of a new genus or sub-genus for such forms, in 
Which case the name Alepidaster might be applied to the group, 
which would probably also include Protaster gregarius of Meek 
and Worthen 
T have intentionally avoided, in the foregoing description, 
the use of the terms ambulacral and adambulacral pieces, 
applied ow some in describing the arms of species of Protaster 
é : 
PALMASTER INcOoMPTUS M. 
Small ; rays rather short, or only about once and a half as 
long as their breadth at the inner ends, and rapidly tapering to 
their outer extremities, which are more or less angular. isk 
equaling in breadth the length of the rays. Dorsal side of rays 
Composed each of three rows of about nine pieces* each, that 
* In some of the rays these appear, but this is probably due to the exposure of 
ue of the marginal rows of the rays by oblique pressure. 
