OCT, 1907: NEw CrINOIDS — SLocom. 289 
vertically and is not visible in a side view of the calyx. In A. 
patulus, however, the opening is in line with the center of the arm 
facets, directed horizontally and visible only in a side view of the 
calyx. 
Locality: The type specimen, Mus. No. P 8417, is a silicified dorsal 
cup in a good state of preservation. It was collected by the writer 
in the clay pockets of the Niagaran limestone at Romeo, in the fall of 
1905S. 
Family CYATHOCRINIDA., 
HOMOCRINUS Hall. 
No members of this genus have been heretofore reported from this 
area, but two species, 1. anctlla and H. cylindricus, were collected by 
the writer and are here described. The generic description is as fol- 
lows: Calyx dicyclic, subcylin- 
drical to turbinate. Infraba- \r 
sals five; basals five; radials tees [rx ag 
five, separated on the posterior Reel 
side by an anal plate. The (*) i eee ) e 
radianal plate is situated below 
the right posterior radial and ea) ea, a O 
between the right anterior Fig. 7. Diagram of Homocrinus. (After Bather). 
radial and the anal plate; ven- 
tral sac long and large; arms bifurcating, without pinnules; stem round. 
Distinguished from Dendrocrinus by the proportionally larger infraba- 
sals and from Potertocrinus by the arrangement of the azygous 
plates. 
HOMOCRINUS ANCILLA Hall, Plate LXXXV, Figures 9-11. 
1879 Dendrocrinus ancilla Hall, Trans. Alb. Inst., Vol. X, p. 9. 
1882 Dendrocrinus ancilla Hall, 11th Geol. Rept. Ind., p. 271. 
1886 Homocrinus ancilla W. & Sp., Revis. Paleocrinoidea, Pt. III, 
Pp. 220. 
Hall’s description of this species is as follows: “Body narrowly 
turbinate, width and height above as ten to twelve or ten to thirteen; 
contracted between the arm bases; upper part of the column closely 
adhering to the body, the five minute basal plates (infrabasals)scarcely 
distinguishable from the segments of the column at its summit; sub- 
radial plates (basals) obscurely angular on the lower face, about 
three-fourths as wide as long, very gradually expanding in width from 
the base, and supporting on their upper adjacent sloping faces a large 
