664 SYSTEMATIC PALEONTOLOGY 



B. External sculpture spinose; margins not serrate. 



1. Altitude and latitude approximately equal; outline subequilat- 



eral Cardium dumosum 



2. Altitude greater than the latitude; outline inequilateral. 



a. Anterior abductor muscle scar inconspicuous or obscure. 



Cardium tenuistriatum 



b. Anterior abductor muscle scar conspicuous .... Cardium kiimmeli 



CARDIUM EUFALENSE Conrad 

 Plate XL, Figs. 1, 2 



Cardium eufalense Conrad, 1860, Jour. Acad. Nat. Sci., Phila., 2d ser., vol. 



iv, p. 282, pi. xlvi, fig. 13. 

 Cardium eufalense Meek, 1864, Check List Inv. Fossils, North America, 



Cret. and Jur., p. 12. 

 Cardium (Trachycardium) eufalense Conrad, 1868, Cook's Geol. of New 



Jersey, p. 726. 

 Cardium (Trachycardium) eufalense Gabb, 1876, Proc. Acad. Nat. Sci., 



Phila., p. 310. 

 Not Cardium eufalense Whitfield, 1885, Mon. U. S. Geol. Survey, vol. ix, 



p. 132, pi. xx, figs. 17-19. 

 Cardium eufalense Weller, 1907, Geol. Survey of New Jersey, Pal., vol. iv, 



p. 577, pi. Ixiii, figs. 17-20. 



Description. " Obliquely ovate, rather thick in substance, profoundly 

 ventricose; ribs about thirty-eight, smooth, prominent, acutely rounded, 

 on the posterior slope angular, compressed or carinated ; summit promi- 

 nent; beaks contiguous." Conrad, 1860. 



Type Locality. Eufaula, Alabama. 



Shell rather small for the genus, obliquely cordate in outline, inflated, 

 the maximum diameter above the median horizontal ; umbones tumid, ele- 

 vated above the dorsal margin, the apices incurved and feebly prosogy- 

 rate, subcentral in position ; dorsal margins approximately straight, the 

 posterior slightly more pronounced than the anterior; anterior lateral 

 margin obscurely truncate, rounding rather abruptly into the dorsal mar- 

 gin and much more broadly into the ventral ; posterior area conspicuously 

 flattened, the lateral margin squarely truncate; base line obliquely arcu- 

 ate ; external surface sculptured with thirty-five to forty vigorous radials, 

 crowded and inclined to be flattened upon their summits in the umbonal 

 region, V-shaped and separated by interspaces of approximately equal 

 width toward the ventral margins; costse twelve to fourteen in number 



