PERMIAN CRINOID FAUNA FROM TEXAS 629 
size, being separated by a vertical suture nearly midway in position 
between the posterior lateral margins of the two. posterior radials, 
the distal extremities extend beyond the level of the radial plates. 
Remarks.—This species is established upon a single dorsal cup 
and is characterized by its broad and deep basal excavation with 
nearly vertical sides, and by the presence of two plates in the pos- 
terior interradial area which is usually occupied by a single anal plate. 
From the single example of the species available for study, it is not 
possible to determine whether this latter character is normal or 
whether it is an abnormal condition. If it is the normal condition 
of the species then the second plate is probably to be interpreted 
as the first tube plate which is not infrequently present in the dorsal 
cup of crinoids in which a radianal plate is present. Its presence in 
this form, however, not associated with a radianal plate is a very 
exceptional condition and might be considered as of generic value. 
ERISOCRINUS PROPINQUUS NH. Sp. 
(Plate I, Figs. 14, 15) 
Description—Dorsal cup basin-shaped, perfectly symmetrical, 
the sutures between the plates flush with the general surface. The 
dimensions of the type specimen are: diameter of the dorsal cup 
18™™, height of same 9.5™™. Underbasal plates forming a slightly 
concave, pentagonal disk 6.5™™ in diameter, the central portion of 
which is occupied by the circular columnar facet 4™™ in diameter. 
Basal plates all similar in form and size, hexagonal in outline, but 
with the two proximal faces meeting in a very obtuse angle and 
together nearly equal in length to one of the lateral faces, so that 
the general outline of the plates is pentagonal, the proximal portions 
of the plates nearly horizontal in position but rapidly curving upward 
so that the major portion of the plates slopes upward and outward. 
Radial plates much broader than high, pentagonal in outline, the 
distal faces bearing well-defined articular ridges. No anal plate 
present. 
Remarks.—This species is established upon a single nearly com- 
plete dorsal cup which resembles and is closely allied to E. typus. 
It differs from that species, however, in the somewhat broader basal 
truncation of the dorsal cup, which is also porportionately higher, 
