Description of New Genera of Echinodermata. i) 
The first primary radials are pentagonal and regularly alternate 
with the subradials, except as interrupted by an azygous plate; 
they are much wider than high ; the upper face is the full width of 
the plate, and projects over the interior of the calyx, so as to make 
a broad articulating face for the first brachial piece; the internal side 
of the first radial is concave; on the upper face of the plates a fur- 
row extends from one angle of the plates to another, on the inner 
side of: which there is a crenulated ridge, for the articulating 
brachial piece, and an interior central depression, and slight con- 
cavity at the central, internal margin. 
There are no regular interradials. A single large quadrangular 
azygous interradial rests obliquely between two subradials and two 
primary radials, and forms part of the wall of the calyx; upon an 
angle of this, at the top of the calyx, a small plate intervenes and 
projects slightly above the first radials. The column is round. 
Other parts unknown, though very thick, heavy plates, bearing a 
spine like the first brachial plate of a Delocrinus, are found asso- 
ciated, and believed to belong to this genus. 
The cup formed by the basal plates distinguishes this genus from 
Eupachycrinus and Delocrinus, both of which have a concave 
~ base and an interior pyramid formed by the basals; the second 
azygous plate does not truncate a subradial, and forms no part of 
the wall of the calyx in this genus, as it does in Eupachycrinus. 
It is probably as nearly related to Delocrinus as it is to Eupachy- 
crinus, though at first view it would seem to be more nearly related 
to the latter. Type U. buttsi. 
ULOCRINUS BUTTSI, n. sp. 
Flate 1., Fig. 5, azygous side view; Fig. 6, basal view. 
The calyx of this species is pyramidal or has the form of half an 
ellipse, elongated; the plates are moderately thick, and convex 
externally so as to throw the sutures into wave-like depressions; 
the sutures are distinct, but the plates are not deeply beveled as 
is common in many species of Eupachycrinus; the surface was, 
probably, strongly granulous, as the better preserved plates are 
rough, though evidently slightly worn. 
The basal plates are large and form a cup about half as high as 
wide; the perforation for the columnar canal is pentagonal and 
