140 ' PALEONTOLOGY OF NEW JERSEY. 



ridge, with a nearly vertical postero-cardinal slope. Beaks lai-ge, promi- 

 nent and attenuated, projecting considerable above the hinge-line. Anterior 

 side of the shell short and regularly rounded; posterior vertically trun- 

 cate and the basal line oblique, being prolonged below toward the pos- 

 terior umbonal angle. Sui-face marked, on the body of the shell at least, 

 by very fine, semi-obsolete, radiating strias, the posterior cardinal slope not 

 showing evidences of striations on the cast, the only condition under which 

 it has been observed. Hinge features unknown. 



The shell has all the generic features of the genus Fragum, as far as 

 can be determined from the external form, while the striations of the surface 

 are much finer than is usually the case; but no ornamentation can be de- 

 tected on the striations, and the features of the hinge are not visible. It is 

 the only form of similar character yet known to me in the formations of 

 the state. 



Formation and locality. — In the lower micaceous clays beneath the 

 Lower Marls, at the Rev. G. C. Schanck's pits, Marlborough, New Jersey. 

 In Professor Lockwood's collection. 



Genus LEIOPISTHA Meek. 



Leiopistha protexta. 



Plate XX, Figs. 1-3. 



Cardium proiextumComaa. J. A. N. S., Phil., 2d ser., Vol. IT, p. 275, pi. XXIV, Fig. 12. 



Papyridea elegantula Gabb. Synop., p. 108. Not of EcBiuer. 



P. protexta (Conrad) Meek. Smitb. Inst., Checklist, p. 12. 



Leiopistha prof exta (Con.) Meek. Geol. Eept. N. Jersey, 1868, p. 726. 



Conrad. Geol. Eept. N. Car. (Kerr's), Append., p. 28. 

 Frag ilia protexta Conrad. J. A. N. S., 2d ser.. Vol. IV, p. 275. 



Shell of moderate size, seldom attaining the length of one and one- 

 fourth inches ; broadly ovate in outline, with strongly inflated valves. 

 Beaks large, prominent, enrolled, usually nearly in contact with each other 

 at their apices, and situated but a little in advance of the middle of the 

 length of the shell. Surface marked by about twenty-four or twenty-six 

 radiating ribs in the larger individuals, with a small space on the posterior 

 end of the shell apparently destitute of radii. In the casts the ribs are 



