Pores ill Fistiilatc Crinoids. — Springer. 143 
which pass from: plate to plate and which run to the angles, 
but in the ridges between them which cross the middle of the 
sides of tlie plates — as in Decadocriniis timiidtilus. This is 
best shown where some plates are turned up on edge, and the 
small pore channels can be seen following the ridges across 
the edge from the exterior to the interior surface, two to each 
plate. An enlarged view of such plates is here given in figure 
7, of PL XVI. 
As to Fig. 7, Scytalocrimis (sp. undet.), I do not deem it 
necessary to refigure this specimen, as it would result in 
producing a duplicate of Mr. Westergren's original drawing. 
By changing the position of the specimen with reference to 
the light, slight differences might be produced. But this 
would not alter the fact that the pores are located at the 
middle of the sides in depressions between the stellate pro- 
jections which run to the angles of the plates — a structure 
which is still more plainly shown in the next figure — fig. 8. 
I have no other specimen of this species showing the ventral 
sac. 
Fig. 8, ScapJiiocrimts sivallovi, was drawn from a speci- 
men from the Burlington limestone, in which the plates are 
very perfectly freed from the matrix, v.diich in this case was 
an extremely fine, soft, yellow, sandy clay, and was removed 
with a soft brush and wetting — leaving the white substance 
of the plates as free as those of a living specimen where the 
soft parts have been dissolved by potash. The apertures at 
the middle of the sides of the hexagonal plates are entirely free 
and open, so that a needle can be passed through many of 
them. They are located in elongate depressions which pass 
from plate to plate on the radial lines, the angles of the plates 
being traversed by ridges. The pores are perfectly open in the 
fossil, forming a channel across the edge of each side of the 
plate at the middle — cut half out of each plate — -so that the two 
in apposition form a more or less circular opening. There can 
be no question here as to whether these depressions pass 
through the plate, for we have the edge of the plate, free of 
all matrix, actually cut away to its full thickness. A single 
plate, by reason of these rounded notches on the sides, be- 
comes hexagonally stellate. In order to show this more 
plainly, I give an enlarged figure of one of these plates and 
