74 TRANS. OF THE ACAD. OF SCIENCE. 
circular, or very slightly elliptical, facet, striated in radii for ar 
ticulating with the column. This perforation is very minute ; its 
orm unkfiown. 
The radial pieces are thick, and about one-fourth wider than 
long. Their lateral margins diverge slightly from below upwards; 
- the superior edges are deeply excavated about two-thirds the 
width of the pieces, to accommodate the two first brachials, and 
on either side of the excavations is a short, oblique, straight edge, 
The inferradial preces, four in number, alternate with the rae 
dials. They are small, a little elongated, hexagonal (?) and very 
slightly concave. 
The brachial pieces are so badly weathered that their charac. 
ters are not to be made out. We only see plainly that there are 
e anal plate, which rests on the base, is tumid above, elon- 
mensions.—Height of calyx, 44 lines; greatest width of 
same, 6 lines; height of base, 14 lines; its great diameter, 43 
— oe a diameter, 33 lines; height of radial pieces, 3 lines; 
width, 
width, about 3 lines 
ocatity.— We possess but a single specimen | 
the Species, the petrifying material of which is silex. It was 
tained from the Archimedes Limestone, at Russellville, Kentueky, 
Where it was found associated with Pentremites florealis. an 
other f : characteristic of that formation. 
-Dicuocrtnus stuprex. ( Shum.) 3 
oe PIT. Fig. 2, a, b. : ae 
The calyz of this little Dichocrinus is bead-shaped, or cylindri- 
co-elliptical, its leneth and b ) at the pit 
rather thin and onesth (? :<treeieenainc medascet = 
kiiots sergery —— and forms about two-thirds the sai 
oF RO Calye. € pieces of which it is composed @f@ 
mech thicker below than above. The facet for articulating with 
the last joint of the column is small, circular, and lies in a deeP 
cavity which is a little wider than the facet. , <e 
” ‘The radial pieces ate higher than wide, evenly convex, @ 
2 
