LAMELLIBRANCniATA OF THE LOWER MARLS. 139 



Genus FULVIA Grey, 1847. 



Fulvia tenuis, u. sp. 



Plate XX, Fig. 8. 



Shell rather small, but little exceeding an inch in length by about half 

 that height; transversely elliptical in outline, and but moderately convex. 

 Beaks very small, appressed, and but very slightly projecting beyond the 

 hinge margin. Anterior end of the shell the shortest, obtusely pointed, or 

 sharply rounded at its extremity, which is situated much above the middle 

 of the height; posterior end more broadly rounded; basal line strongly 

 arcuate and rapidly ascending toward the anterior part. Hinge-line but 

 little declining on either side of the beak. Surface of the valve marked by 

 radiating plications which are very fine at the anterior end, and gradually 

 increase in strength to the extreme posterior margin, where they must have 

 been fully one-sixteenth of an inch wide (the shell being broken at this 

 point). Plications flattened obliquely, so as to give the antei'ior side a 

 much greater abruptness and only about one-third the width of the pos- 

 terior side. A few concentric undulations mark the surface, and very fine 

 concentric striae cover the entire shell. 



This is the fii'st species of this section of the Gardiidce which I remem- 

 ber to have seen from the Cretaceous formations. But I think there can be 

 no doubt as to the correctness of the generic reference, although the hinge 

 features are not observable. It has somewhat the appearance of a Linearia 

 Conrad, but difi'ers in its general form, and particularly so in the regular 

 increase in strength of the striiB, which will readily distinguish it from 

 specimens of that genus found in the New Jersey beds. 



Formation and locality. — A single slightly imperfect valve (partial cast) 

 occurs in the cabinet at Rutgers College, marked " Holmdel, Monmouth 

 Co., N. J.," and had been labeled ^' Pholadomya." 



Genus FRAGUM Bolton. 



Fragum tenuistriatum, n. sp. 

 Plate XX, Fig. 15. 



Shell below a medium size, irregularly trapezoidal or sub-triangular in 

 outline, highly ventricose and sharplj' angular along the posterior urabonal 



