OE DENISON UNIVERSITY. 
57 
the layer a few feet below congl. L The species is also found forty 
feet below congl. I, at Union Station, in large, finely preserved speci- 
mens, a left valve measuring in length, 25 mm, in width 23.5 mm. 
Strehlopteria squama, sp. n. 
(Plate VII, Fig. 14. ) 
Smaller or medium size, with extended hinge-line and ovate out- 
line. Left valve quadrately ovate ; length and height about equal ; 
hinge about three- fourths the length ; anterior outline nearly straight, 
slightly convex below and concave at the ear ; posterior outline gently 
and uniformly convex ; .anterior wing largest, nearly rectangular, not 
very distinctly separated from the body; moderate posterior ear ob- 
tusely angular, passing without interruption into the general surface of 
the body ; surface slightly convex, ornamented only by fine, crowded 
imbricating lines, epidermis very thin. Shales below congl. I. 
This species is considerably smaller than the average specimens 
of S. media and is more broadly ovate, with a longer hinge-line. No 
traces of radiating striae could be seen. 
Strehlopteria gracilis, sp. n. 
(^Plate VII, Fig. 12.) 
Shell of medium size, elongate, with very short hinge. 
Left valve narrowly elliptical, length four-fifths the height, hinge 
less than half the length ; posterior margin a uniform slight curve to 
the almost obsolete ear ; anterior margin very abruptly flexed at the 
umbonal slope to the short, obtusely triangular ear; surface convex, 
ornamented by concentric and obscure radiating lines. Free-stone of 
middle Waverly (?) This species resembles the larger form of S. media, 
but is at once distinguished by its narrower form and short hinge-line. 
Pernopecten shumar dianus , Win. ? ? 
(Plate XII, Figs. 13-^.) 
A considerable number of nearly perfect valves are represented 
