308 The American Geologist. May, 1902. 
and breadth and low conical in outer surface features. Above 
this latter are two much smaller nodose plates. The large 
anal interradial is a little deeper than wide and with conical 
outer surface. Three somewhat smaller ridge-like plates rest 
upon this and above them three still smaller nodose plates 
The dorsal cup itself is obconical with length and width 
about equal. The ventral disk is conical and hardly so deep 
as the dorsal cup. The plates of the latter are much less 
strongly nodose than those of the dorsal cup. 
The base of the anal tube is strong and the plates heavy, 
leaving but a small canal in the anal tube. The lobes formed 
by the arm bases are not strongly marked, hardly noticeable, 
in fact. The left posterior ray supports but three arm bases 
while the right has four, the right and left antero-lateral, four 
each, while the anterior itself has but two—17 in all. The 
column is small and with a small central perforation. Arms 
unknown. 
This crinoid has characters allying it to Lobocrinus, Eret- 
mocrinus and Batocrinus. In the depth of its ventral disk © 
it differs much from the two preceding species of Lobocrinus 
and may have to be removed to Eretmocrinus or Batocrinus, 
to both of which it seems closely related. 
Lower Burlington limestone, White Ledge, Mo. 
EretmocrinuSs? parvus, pn. sp. 
PLATE XVIII. 
Fic. 14. Side view of the type specimen. 
The expansion of the dorsal cup from the basal plates tu 
the arm bases is but little. The three basal plates are heavy 
for so small a body, while the first radials are large and rathet 
extravagantly produced outward into wart-like nodes. The 
second radials are very small, quadrangular and without ele- 
vation above the general surface. The third radials are pen- 
tagonal and hardly nodose. The radials of the second series 
consist of a primary plate, longer than wide, and an axillary 
piece supporting the arm bases. The only plate of the inter- 
radial series is rather small and wart-like. (There is appar- 
ently a want of other plates above.) The large azygous plate 
is of equal length and width and strongly nodose. Above it 
appears to be but one small nodose plate. The ventral disk 
is but moderately elevated, has but few plates and most ot 
