OF DENISON UNIVERSITY. 
97 
acute posterior angle at a point below half the height; posterior mar- 
gin slightly concave, inclined to the longitudinal axis about 40°, mak- 
ing an angle of about 150° with the declined hinge margin. Greatest 
convexity of valves near the beak, from which a strong post-umbonal 
ridge passes to the posterior angle, above which the surface is concave; 
entire surface marked by fine thread-like, closely arranged striae. Al- 
though our specimens are rather strongly produced and the interior 
could not be seen there is little doubt of the generic reference. 
Length 24 mm. (19-17); height 15 mm. (ii-ro. ) Freestone of 
middle Wavery, Union Station. W. F. Cooper collector. 
d'his species may be compared with Sch. nuculiformis or Sch. ob- 
scurus, Dekoninck. 
Conocardiuin pulchellinn, White and Whitfield. 
(Plate I, Fig. 12; Plate VII, Fig. 39, Fig. 40?) 
“Shell small, general form triangular, with ventricose valves. 
Flinge line straight, the length equal to that of the posterior slope. 
Anterior end cuneate ; posterior end obliquely truncate. Basal line 
gently arcuate, widely gaping near the anterior extremity ; hiatus elon- 
gate ovate, distinctly crenulate on the inner border. Beaks minute, 
incurved, situated posteriorly ; umbonal slope rounded, posterior space 
concave; siphonal tube small. Entire surface marked by distinct, di- 
verging radii, those of the posterior space a trifle finer than those of the 
body of the shell; also by very fine concentric striae. Greatest length 
.4 inch.” 
Identified from Newark by Winchell. fAm. Philos. Soc. Vol. 
XII, p. 256.) 
It seems to be common at Granville, also, in the free stone of 
middle Waverly. 
Another species is represented, but is known only from distorted 
specimens. (See Fig. 41, Plate VII.) 
