156 PALEONTOLOGY OF NEW JERSEY. 



Genus CYPEIMEEIA Conrad. 1864. 



(Proc. Acad. Nat. Sci. Phil., p. 212.) 



Cyprimeria depressa. 



Plate XXII, Figs. U-13. 



Dosinia depressa Conrad. J. A. N. S. Phil., new ser.. Vol. IV, p. 278, PI. XLVI, Fig. 6. 

 ? Sanguinolaria cretacea Con. J. A. N. S., new ser., Vol. IV, p. 277, PI. XLVI, Fig. 



11. Gabb, Proc. A. N. S., 1876, p. 308. 

 Dosinia Haddonfieldensis Lea. P. A. N. S., 1861, p. 149. 

 I). depressa (Con.) Gabb. Synopsis, p. 120. Meek, Check list, p. 13. 



Cyprimeria Cretacensis Conrad. Am. J. Conch., Vol. Ill, p. 9. 

 C. Cretacea Con. Am. J. Conch., Vol. II, p. 102. 



C. depressa Conrad. Kerr's Kept. Geol. Surv. N. Car., Appendix, p. 9. 



C. depressa (Con.) Gabb. P. A. N. S., 1876, p. 308. 



Shell of medium size, transversely broad-ovate in outline, with very- 

 depressed convex valves, which are broadest anteriorly and somewhat sub- 

 cuneate behind, althouorh slightly truncate at the narrow extremity. Beaks 

 very small, inconspicuous, situated a little nearest the anterior end of the 

 valve, and pointed. Postero-cardinal margin rapidly sloping from the beaks 

 to the posterior truncation, and but very little arched in its coui'se; more so 

 on the left valve, and almost invariably a little humped at about one-third 

 of the length behind the beak on the right valve. Basal line strongly 

 rounded, fullest just in advance of the middle. Right valve the most con- 

 vex and bent downward at the posterior, while the left valve is curved or 

 bent upward to correspond, giving a rather strong twist to the valves as 

 seen in a basal view. Surface of the shell marked by regular concentric 

 lines of growth and numerous stronger varices at irregular distances. Near 

 the apex of nearly all valves the surface is marked by regular concentric 

 ridges when seen under a glass, which are lost at from a fourth to three- 

 eighths of an inch from the beaks. When the valves are united the lunular 

 depression is but slight, but behind the beaks the margins of the valves are 

 strongly inflected and form a deeply excavated escutcheon, like that of 

 Circe, while the beaks of the two valves nearly touch each other. In the 

 interior the hinge-plate is rather wide, the muscular imprints faintly marked 

 but large, and the pallial line quite distinct but not sinuate. 



Internal casts of the species appear to be comparatively rare, at least 

 in a condition to be identified. On them the beaks seem to be much larger, 



