Say on Shells, &c. 237 
tive examination of its characters, exhibits its inseparable 
connection with the family of Encrinites by the analogy of 
its mode of support, its rectilmear sutures, and the general 
form of its pelvis or basal portion. 
To the base is generally attached, the single superior 
joint of the trunk or vertebral column ; this joint is short, 
and is longitudinally divided by three sutures, which radiate 
from a central foramen; its inferior articulating surface is 
orbicular, with numerous marginal radi, and the centre ex- 
hibits the opening of the foramen; at its junction with the 
ossa innominata itis somewhat trilobate. ‘The ossa innomi- 
nata are of a rhomboidal form, sometimes pentagonal or 
subquadrate. ‘The pelvis has the same general form with 
that of the Encrinus liluformis, but the angles of the penta- 
gon are much more acute, and those parts which Parkinson 
denominates ribs, clavicles and seapule are not distinct. 
From the superior angle of each of the ossicule of the 
base, a suture ascends, bisecting each of the interstitial spa- 
ces, and is divaricated near the tip, so as to give to those 
triangular spaces, arhombric termination. Each of the five 
outer foramine, (of which one is mvariably much the lar- 
gest) is the common aperture of two tubes which penetrate 
to the tips of the ambulacra, immediately beneath the su- 
tures of those parts, and which are not visible but by dis- 
section ; the central foramen is stellate. 
The peculiar adaptation of these various parts to each 
other, may have permitted their independent movement, in 
order that the animal might assume some form of expan-. 
sion; but we are led to suppose that this motion could not 
have been very considerable, from the relative situation of 
the sutures. And I may further add, that, as we have no 
direct proof that this animal did possess the power of ex- 
panding, it may be, that the motion of its body was confined 
to the protrusion of tentacula through the foramina, and per- 
haps smaller ones through the pores of the Ambulacre. 
This question, however, must remain for the solution of 
future observers, who may have an opportunity to examine 
them in situ, and of comparing together their different frag- 
ments which may be discovered. All the specimens which 
I have seen, about sixty in number, are in a perfectly similar 
collapsed state. 
