634 CRETACEOUS PALEONTOLOGY. 



concentric lines of growth. Muscular scars proportionally large 

 and moderately distinct, and an indication of a rather deep sinus 

 in the pallial line." (Whitfield) . 



Remarks. — "This species differs from C. lintca in the more 

 transverse form, less angular umbonal ridge, which is also situ- 

 ated nearer to the cardinal border ; in the less elevated form and 

 more arcuate basal margin, and also conspicuously in want of 

 the coarse, regular, concentric markings of the surface seen on 

 that one. In regard to its generic affinities there may be a little 

 doubt, as the hinge has been much less thickened and consequently 

 the impressions of the teeth are less conspicuous and consequently 

 less certain." (Whitfield). 



Formation, and locality. — Wenonah sand, near Marlboro 

 (Whitfield). 



Geographic distribution. — New Jersey. 



Genus Schizodesma Gray. 

 Schizodesma appressa Gabb. 



Plate LXXI., Pigs. 14-2T. 



1876. Schizodesma ? appressa Gabb, Proc. Acad. Nat. Sci. Phil. 



(1876), p. 306. 

 1886. Veleda transversa Whitf., Pal. N. J., vol. i (Monog. U. 



S. G. S., vol. 9), p. 174, pi. 23, fig. 22. 

 1905. Schizodesma. appressa Johns., Proc. Acad. Nat. Sci. Phil. 



(1905), p. 17. 



Description. — The dimensions of an average right valve are: 

 length, 23 mm.; height, 15.5 mm., convexity, 4 mm. Shell 

 inequilateral, subovate or ovate-subcuneate in outline. Anterior 

 and posterior cardinal margins meeting at the beak at an angle 

 of about 125"; anterior margin regularly rounding from the 

 antero-cardinal margin above into the basal margin below ; basal 

 margin gently convex throughout, becoming a little straighter 

 postei4orly ; postero-basal extremity subangular ; posterior margin 

 shorter than the anterior, obliquely truncate; posterior cardinal 

 extremity obtusely subangular. Beaks prominent, nearly erect, 

 slightly incurved, situated a little in front of the middle of the 

 shell. Valves most prominent on the umbo, sloping rather ab- 



