MOLLUSCA. 581 



about 60 to 64 radiating ribs which are impressed upon the casts- 

 tip to the umbonal region. 



Remarks. Whitfield's figure 17 of his Cardium eufaulensis is 

 possibly a representative of this species, but it is proportionately 

 somewhat narrower than any of the specimens which have been 

 observed. The species differs from C. eufaulensis in its more 

 nearly circular form, its straighter and practically horizontal 

 hinge-line, and its much larger number of costae. It is also much 

 larger than the original illustration of that species. 



Formation and locality. Woodbury clay, Lorillard (102). 



Geographic distribution. New Jersey. 



Cardium cliffwoodensis n. sp. 

 Plate LXIV., Figs. 1-4. 



Description. The dimensions of the internal casts of two 

 valves, the larger a right and the smaller a left valve, are : 

 height, 25 mm. and 18 mm.; width, 25 mm. and 18 mm.; con- 

 vexity, 7 mm. and 6 mm. Shell obliquely subovate in outline; 

 hinge-line arcuate; the anterior and basal margins from the an- 

 terior cardinal extremity to the postero-basal extremity, describe 

 a nearly regular semicircle; postero-basal margin more sharply 

 rounded; posterior margin gently convex, straighter than the 

 anterior margin. Beaks situated near the middle of the hinge- 

 line, small, acute, slightly elevated above the hinge-line in the 

 internal casts. Valves only moderately convex; anterior slope 

 long and regularly convex; posterior slope much shorter, more 

 abrupt, slightly flattened. Muscular impressions on the casts 

 inconspicuous. Lateral hinge-teeth strong, sloping slightly 

 downward from the beak on each side ; characters of the cardinal 

 teeth not clear in the casts. Inner free margin of the shell 

 strongly crenate. Surface of the shell marked by about 35 or 

 40, squarish, flat-topped, radiating costae, slightly wider than the 

 interspaces, and by fine concentric lines which are stronger upon 

 the tops of the radiating costae. 



Formation and locality. Cliffwood clay, Cliffwood Point 

 (185), near Matawan (107). 



Geographic distribution. New Jersey. 



