OF DENISON UNIVERSITY. 
45 
rounded, at least one-third length of valves from anterior margin ; 
hinge line straight behind the beak ; posterior umbonal ridge rounded,, 
not carinate ; surface with imperfectly preserved fine lines of growth.. 
This species obviously differs from the three above described. It 
would seem to resemble S. a77ipliis, but in that the posterior margin is 
said to be vertically sub-truncated, also the posterior umbonal slope 
has a distinct sulcus not seen in this species. 
Genus Placunopsis,* Morris and Lycett. 
Placiinopsis recticardinalis , Meek. 
(Plate IV, Fig. II.) 
This species was described from Flint Ridge and hence the figure 
given by Meek is copied, although we have not found the shell as yeL 
Genus Posidonomya, Brown. 
Posidonoinya fracta, Meek. 
Only fragments of this shell which, as Meek says, is almost an 
exact miniature of the cretaceous Inoceramus problematicus were 
found. 
BRACHIOPODA. 
Lingula tighti, sp. n. 
(Plate IV, Fig. 5 .) 
This name is proposed for a Lingula of medium size found in 
great numbers upon the lamellae of earthy portions of fissile canneE 
coal at Flint Ridge, ten miles east of Newark, Ohio. This coal seam, 
is number two in the section and has furnished considerable quantities;, 
of fairly good coal to local consumers. The Lingulae occur in great 
numbers, covering the surface in places completely, and the coal is; 
filled with them for a thickness of several inches. Valves nearly sim- 
ilar, elliptical, somewhat asymetrical ; one margin nearly straight, the 
other more strongly curved, sides narrowed anteriorly .and then rather 
abruptly rounded ; width equal to over one-half the length; beak near- 
er the straight margin ; shell covered with brown, finely striate epid- 
ermis, which is well preserved ; striae very numerous, crowded, but 
