PERMIAN CRINOID FAUNA FROM TEXAS 625 
not symmetrically so as are the other three. The radial plates 
large, about twice as wide as high, pentagonal in outline, marked 
by strong articular ridges on their distal faces. Radianal plate large, 
its width about two-thirds its length, its area about equal to that of 
the adjacent basals, its general outline quadrangular but really 
pentagonal, the distal face supporting the first tube plate being very 
short, the proximal angle of the plate in contact with the distal angle 
of the right posterior underbasal. Anal plate imperfectly preserved 
in the type specimen, but apparently smaller than the radianal. 
The first tube plate is incorporated in the calyx at least in its proxi- 
mal region. 
Neither the arms nor the ventral sack of the species have been 
observed, but accompanying the dorsal cup are a number of large, 
spatulate, spinous plates which characteristically form the border 
of the distal surface of the mushroom-shaped ventral sack in this 
genus. These plates probably represent the same species as the 
cup, and their form and size is such as to indicate that about 15 of 
them formed the border of a disk 60 or 70™™ in diameter, exclu- 
sive of the spinous projections of the plates. 
Remarks.—This species is characterized by its great size, the only 
form at all comparable with it in this respect being Hl. kansasensts 
from the upper Pennsylvanian of Kansas which is nearly of equal 
size. It differs from the Kansas species in its smaller underbasal 
disk, in the deeply excavated base for the attachment of the column, 
in the slighter contact of the radianal plate with the underbasals, 
and especially in the outline of the basal plates which are pentagonal 
rather than triangular. 
PHIALOCRINUS AMERICANUS Ni. Sp. 
(Plate I, Figs. 8, 9) 
Description.—Dorsal cup large, subglobose, the diameter of the 
type specimen approximately 47™™ and its height approximately 
30™™, The surface of the plates smooth, all the sutures except 
those between the underbasals situated in shallow and narrow 
grooves. Underbasals forming a shallow, saucer-shaped basin 
which is visible in a side view, its diameter being about 22™™ in 
the type specimen, the stem facet but slightly depressed below the 
