636 CRETACEOUS PALEONTOLOGY. 



enrolled beaks, which are directed forward and project consider- 

 ably beyond the line of the hinge. Posterior hinge border gently 

 arcuate, extending more than two-thirds of the distance from the 

 beak toward the basal margin of the shell. Postero-basal angle 

 sharply rounded, and the basal margin broadly arched ; anterior 

 end less sharply and more regularly rounded than the postero- 

 basal. Surface of the shell, as indicated on the partial casts and 

 imprints left in the hardened clay, smooth or marked by fine lines 

 of growth only. On the cast of a right valve there are indications 

 of two principal cardinal teeth beneath the beak, and a long, 

 rather slender, lateral tooth. The muscular impressions are not 

 visible on the posterior side, but on one specimen the anterior 

 scars seem to have been large and deep; but this feature is not 

 very satisfactorily determined." (Whitfield.) 



Formation and locality. Raritan clay, Sayreville and near 

 Woodbridge (Whitfield).- 



Super-family MYACEA. 



Family COBBULIDAE 



Genus CORBULA Lamark. 



Corbula manleyi n. sp. 



Plate LXXIL, Figs. 1-8. 



Description. The dimensions of a perfect specimen are: 

 length, 15 mm.; height, 10.3 mm.; thickness, 7.8 mm. Shell 

 inequivalvate, subcuneate, subtrigonal in outline; beaks promi- 

 nent, incurved, nearly in contact, situated at or a little in front of 

 the anterior third of the shell. Anterior and posterior cardinal 

 margins meeting at the beak in an angle of about 100, anterior 

 slope much shorter than the posterior ; anterior margin rounding 

 regularly from the cardinal into the basal margin; basal margin 

 slightly convex in front, becoming straight behind ; postero-basal 

 extremity angular; posterior margin very short, curving almost 

 immediately into the post-cardinal margin above; post-cardinal 

 margin long, nearly straight. Valves ventricose in the umbonal 

 region, the surface curving abruptly and inflected to the antero- 

 cardinal margin; sloping rather steeply with a slightly convex 



