122 PALEONTOLOGY OF NEW JERSEY. 



Formation and locality. — In the Lower Marl Beds at Bruere's pits, on 

 CJrosswicks Creek, near Walnford, and near Cream Ridge, New Jersey. 

 Mr. Conrad's types which are here figured were obtained from Arneytown, 

 New Jersey, and borrowed from the Academy of Natural Sciences of Phila- 

 delphia. 



Crassatella transversa. 

 Plate XVII, Figs. 16 and IT. 



Crassatella transversa Gabb. P. A. K Sci., Phil., 1861, p. 364. Synopsis, p. — . Meek, 



Checklist, p. — . Geol. Surv. N. J., 1868, p. 726. 

 Mea transversa (Gabb) Conrad. P. A. K Sci., Phil., 1876, p. 275. 



Known from a single internal cast, representing a shell of moderate 

 size, with proportionally ventricose valves, which have a transverselv 

 elongated form and rather prominent erect beaks, situated at about the 

 anterior third of the length, and are rather distant from each other in the 

 cast. The anterior end is rather broadly rounded, and the posterior part 

 prolonged and narrow, with the extremity pointed below and curved down- 

 ward, leaving the basal line somewhat broadly sinuate in the posterior third, 

 and very strongly convex opposite the beaks. The muscular scars have 

 been large and deep, being ver}^ strongly marked and prominent on the casts, 

 and the pallial line strong, with the border of the valve outside of the line 

 very much thickened and the margin strongh^ crenulate. 



The cast representing this species, that used by the author in the 

 original description, is very much more transverse than any other described 

 from New Jersey, except C. Delawarensis of the same author. It is a larger 

 species, however, than that one, and of an entirely different form, being 

 destitute of the angularity of the umbonal region, and more narrowed and 

 curved posteriorly with a rounded anterior end. In form it presents many 

 features in common with C. protexta Conrad, from the Eocene sands at 

 Claiborne, Ala., but has been a much more ventricose and thicker shell, 

 with larger and more distant beaks, and more strongly marked muscular 

 scars. It would appear to have been a ver}^ rare species, as I have observed 

 ^only the one cast among all the collections which I have examined. 



