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 stri^. Al- 

 though our specimens are rather strongly produced and the interior 

 could not be seen there is little d()-i')t of the generic reference. 



Length 24 mm. (19-17); height 15 mm. (ir-io.) Freestone of 

 middle Wavery, Union Station. W. F. Cooper collector. 



I1iis species may be compared with Sch. nuculiformis or Sch. ob- 

 scurus, Dekoninck. 



Conocardiunv pulchellinn, White and Whitfield. 

 (Plate I, Fig. 12; Plate VII, Fig. 39, Fig. 40?) 



"Shell small, general form triangular, with ventricose valves. 

 Hinge 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 strii\i. (rreatest length 

 .4 inch." 



Identified from Newark by Winchell. f Am. 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.) 



