Description of New Genera of Echinodermata. 9 
the second azygous plate; they are twice as wide as high; the 
upper face is the full width of the plate, and extends internally 
nearly one-third the diameter of the calyx; in the specimen 
described the width of the calyx is 1 3-10 inches, and the projec- 
tion of these plates 4-10 inch, leaving the opening at the top of the 
calyx only 1-2 an inch, while the great concavity on the inner 
side of these plates will give an internal diameter of the calyx 
immediately below the top of the first radial of nearly an inch; 
the upper surface is broader than it is in E. buttsi, but the mark- 
ings for the articulating brachials seem to be about the same. 
The azygous plate forms part of the calyx, is quadrangular, 
nearly as large as a first radial, rests obliquely between two sub- 
radials and the under sloping side of the right first radial and a 
second under sloping side of the left first radial; the upper angle 
extends about as high as the upper face of the radials, and is very 
a slightly if at all truncated by an angle of the small second azygous 
plate. 
This species is remarkable for the great overlapping or interior 
projection of the first radials, and in this respect exceeds all known 
species of Delocrinus and Eupachycrinus. No part above the first 
radials is known, but some equally remarkably thick brachial plates, 
each bearing a very large spine, occurring at Rock Creek, in Jeffer- 
son County, Kansas, appear to belong to this species. 
Found at Kansas City, Missouri, and now in the collection of 
Min Em. Gurley. 
DELOCRINUS, 1. Seno. 
Ety.: delos, manifest, clear ; &rvnon, lily. 
The species belonging to this genus are usually robust, calyx 
basin-shaped, arms broad, composed of a double series of inter- 
locking pieces joining neatly with each other, column round, plates 
thick, and surface smooth or finely granulous, not sculptured; 
basals five, occupying a concavity on the under side, and more or 
less hidden by the column, but forming a little cone in the interior 
of the calyx; subradials pentagonal and hexagonal, larger than the 
basals, the lower part inflexed by the depression of the base to 
meet the basal plates, the middle regularly arched, and the upper 
part forming a more or less acute angle between the under sloping 
sides of the first radials; first radials wider than high, pentagonal, 
