MOLLUSCA. 599 



Formation and locality. Cliffwood clay, Cliffwood Point 

 (105, 185), near Matawan (186, 107, 189); Woodbury clay, 

 near Matawan (103) ; Wenonah sand, near Marlboro (130). 



Geographic distribution. New Jersey, Texas. 



. Isocardia tintonensis n. sp. 



Plate LXVL, Fig. 9. 



Description. The dimensions of the type specimen are : length, 

 28 mm. ; height, 23 mm. ; convexity of one valve, 9.5 mm. Valves 

 subtriangular in outline, with prominent umbo and strongly 

 incurved beaks situated about three-sevenths of the length of 

 the shell from the anterior extremity. The anterior margin 

 rounding from beneath the beak into the ventral margin, the 

 curvature sharpest at the most anterior point, basal margin gently 

 convex, curving upward in front and behind, the postero-basal 

 extremity rather abruptly rounded into the posterior margin, 

 which is obliquely subtruncate below and curving forward above 

 to the post-cardinal margin. Valves most prominent on and just 

 below the umbo, the anterior slope abruptly convex ; the posterior 

 slope convex and rather gentle to the rounded umbonal ridge, 

 beyond which it becomes very abrupt and a little concave, 

 especially above. Surface of the internal cast smooth, the shell 

 itself probably marked by concentric lines of growth. 



Formation and locality. Tinton beds, Beers Hill cut (i29 5 ). 



Geographic distribution. New Jersey. 



Isocardia conradi Gabb. 

 Plate LXVL, Figs. 13-14. 



1860! Isocardia conradi Gabb, Jour. Acad. Nat. Sci. Phil., 2nd 



ser., vol. 4, p. 393, pi. 68, figs. 2 1-21 a. 

 1861. Glossus conradi Gabb, Synop. Moll. Cret. Form., p. 186 



(130). 

 1864. Glossus conradi Meek, Check List Inv. Foss. N. A., Cret. 



and Jur., p. 12. 



