OcT., 1907. NEw CrINOIDS — SLOcom. 299 
Locality: The species is represented by a single individual collected 
by the writer in the fall of r905, in the Niagaran limestone in the spoil 
heaps along the Chicago Drainage Canal, about one mile east of 
Lemont, Illinois. 
Family THYSANOCRINID. 
THYSANOCRINUS Hall. 
Weller’s description* of this genus is as follows :— 
“Calyx subglobose, urn or bell-shaped, the rays marked by more or 
less conspicuous ridges; the surface of the plates smooth, or variously 
ornamented. Infrabasals five small, barely extending beyond the 
column, or entirely hidden by 
it. Basals five, four of them 
equal and angular above; the 
fifth truncated and support- 
ingalargeanal plate. Radi- 
als considerably larger than 
the costals, their proximal 
sides distinctly angular, the 
lateral faces comparatively 
short. Costals two. Distich- 
als two or three in each series. 
In some cases palmers are 
also present, the axillary dis- 
tichal giving rise on the inter- 
radial side to an armlet for Fig. 11. Diagram of Thysanocrinus. 
the most part included in the 
calyx and on the other side of the main arm. Four of the first inter- 
brachials large, angular below, resting upon the sloping upper corners 
of the two radials and against the costals; two plates in the second 
row, often followed by smaller ones above which connect with the 
plates of the disc. The anal side considerably wider, the first plate 
large, hexagonal, resting upon the truncated posterior basal, three 
plates in the second row and smaller ones above. In some species 
an uninterrupted row of anal plates extends to the anal opening. 
Interdistichals generally represented and rather large. Column 
round or obtusely pentangular.”’ 

THYSANOCRINUS CAMPANULATUS sp. nov. Plate LX XXV, Figs. 20-23. 
The calyx is bell-shaped, expanding very rapidly above the top of 
Pastiiied v. -Pt. L, Nat. Hist, ourv., Chicago Acad. Sci., p.-70. 
