On Lingulasma , Etc .— Ulrich. 
381 
cinnati specimen. The two snlci distinguish it from all the 
other specimens known to me. | 
Formation and locality : Lower beds of the Cin. gr. about 
75 ft. above low water mark in the Ohio river at a cut of the 
C. S. R. R. just opposite Cincinnati, Ohio. The specimen was 
found by Mr. Harold Wilson and now belongs to the cabinet 
of Mr. Charles Schuchert. 
LINGULA WHITFIELD I, n. sp. 
Fig. 3, 3 a, 3 b. 
Shell rather large, broadly oval, the rostral margin nar¬ 
rowly rounded, with the beak small and scarcely, if at all, pro¬ 
truding. Sides for about the third of the length next the beak 
nearly straight. Anterior two-thirds uniformly curved, this 
portion of the outline being very nearly circular. Beak of 
ventral valve a little more produced than that of the dorsal, 
the length and breadth of the latter being respectively as 
eight is to seven, while these measurements in the ventral 
valve relate to each other as twelve is to ten. Outer surface 
with rather irregular concentric striae, some of them often 
thread-like and stronger than the average. They are, however, 
rarely continuous and never so regularly disposed as in the 
associated L. coburgensis Billings (Z. covingtonensis Hall 
and Whitfield). Both valves moderately convex, with the 
most elevated point near the middle. Color white to yellow¬ 
ish brown. A large valve supposed to be the ventral, is 24.3 
mm, long, 20 mm. wide and 3.0 mm. deep. 
Interior of dorsal valve roughly pitted, the pits numerous, 
small, unequal and generally irregularly arranged but some¬ 
times exhibiting a tendency to an arrangement in concentric 
rows. The muscular impressions which are faintly indicated? 
form a figure something like an 8. The two halves of the 
figure are drawn out anteriorly, and the posterior half smaller 
than the anterior. 
This species is related to Z. coburgensis Billings, but differs 
from it in being comparatively shorter and wider in front. 
Z. obtusa Hall, is smaller and narrower; Z. curta Conrad, has 
a more acute beak; Z. perryi Billings, differs in its form 
being sub-triangular in outline. The pitting of the interior 
surfaces of the valves distinguishes this species from all 
others known to me, save one, which occurs in the same beds 
with it and begins already in the middle Trenton beds of cen- 
