MOLLUSCA. 583 



1905. Cardium ripleyanum Johns., Proc. Acad. Nat Sci. Phil. 

 (1905), p. 15. 



Description. The dimensions of an internal cast are : height, 

 4.5 mm. ; width, 4 mm. ; thickness, 3 mm. The height of one of 

 the largest individuals observed is 5.3 mm. Shell subcircular in 

 outline, slightly higher than wide, cordate in end view. Hinge- 

 line relatively long, a little arched; anterior, basal, and posterior 

 margins rounded. Beaks rather prominent, elevated above the 

 hinge-line, incurved. Umbones prominent, the surface sloping 

 rather abruptly both in front and behind; shell compressed to- 

 wards the cardinal extremities, more so behind than in front. 

 Surface of the shell marked with about 22 subangular, radiating 

 ribs, slightly narrower than the interspaces, also by fine, con- 

 centric, sublamellose lines. 



Remarks. This little species is not an uncommon member of 

 the Woodbury clay fauna, being less common in the Cliffwood 

 and Merchantville. It was originally described from. the Wood- 

 bury clay formation near Haddonfield. 



Formation, and locality. Cliffwood clay, Cliffwood Point 

 (105), near Matawan (189); Merchantville clay, near James- 

 burg (139, 140, 141), Lenola (163); Woodbury clay, Lorillard 

 (102), near Matawan (103), near Haddonfield (183, 168, 165, 

 164). 



Geographic distribution. New Jersey. 



Cardium spillmani Conrad. 

 Plate LXIV., Figs. 9-11. 



1858. Cardium spillmani Con., Jour. Acad. Nat. Sci. Phil., 2nd 



ser., vol. 3, p. 326, pi. 34, fig. 3. 

 1864. Cardium (Liocardium) spillmani Meek, Check List Inr. 



Foss. N. A., Cret. and Jur., p. 13. 

 1886. Cardium (Protocardium) perelongatum Whitf., Pal. N. 



J., vol. i (Monog. U. S. G. S., vol. 9), p. 136, pi. 20, 



figs. 202 1, pi. 21, figs. 4-5. 



