382 CRETACEOUS PALEONTOLOGY. 



Remarks. — This species has only been found in the Wood- 

 bury clay. At Lorillard it is one of the most abundant species,, 

 and like so many of the shells at this locality, it attains a much 

 larger size than at Haddonfield. The number of hinge-teeth 

 in the Lorillard specimens is also greater than in those from 

 Haddonfield, but this is doubtless due to their larger size. In 

 some of the internal casts from Lorillard a deep pallial sinus is 

 faintly seen, which gives to the shells the characteristic features 

 of the genus Yoldia. The species is a close ally of Yoldia evansi 

 M. & H. of the Cretaceous faunas of the interior. 



Formation and locality. — Woodbury clay, Lorillard (102), 

 near Matawan (103), Crosswicks (168), near Haddonfield 

 (183, 165, 164). 



Geographic distribution. — New Jersey, Mississippi, Arkansas.. 



Yoldia papyria (Conrad). 

 Plate XXX., Fig. 6. 



i86g. Nucularia papyria Con., Am. Jour. Conch., vol. 5, p. 44,. 



pi. I, fig. 7. 

 1886. Nucularia papyria Whitf., Pal. N. J., vol. i (Monog. 



U. S. G. S., vol. 9), p. Ill, pi. II, figs. 18-20. 

 1905. Nucularia papyria Johns., Proc. Acad. Nat. Sci. Phil.. 



(1905), p. 8. 



Description. — The dimensions of a large right valve are: 

 length, 15.5 mm.; height, 9.5 mm.; convexity, 3 mm. Shell sub- 

 elliptical in outline, strongly convex in the anterior half, becom- 

 ing rapidly depressed posteriorly. Beak scarcely elevated above 

 the hinge-line, situated a little over one-fifth of the length of 

 the shell from the anterior extremity. Posterior portion of 

 the hinge-line nearly straight, the hinge-plate bearing about 

 18 >-shaped teeth; the anterior hinge-line much shorter than 

 the posterior, rapidly declining, forming an angle of about 

 125° with the posterior portion, the hingle^plate bearing about 

 12 (-shaped teeth. Anterior margin of the shell rounded from 

 just below the beak to a point on the ventral margin directly 

 beneath, the curve being subsemielliptical with the most anterior 



