FREE INSTITUTE OF SCIENCE 



1433 



TERTIARY FAUNA OF FLORIDA 



Shell small, solid, rounded or ovate, slightly inequilateral, with a lanceolate 

 escutcheon and a subcordate, smooth, impressed lunule; sculpture of twelve 

 or thirteen narrow, squarish, closely nodulous radial ribs separated by wider 

 interspaces, faintly concentrically striated; beaks rather low, slightly proso- 

 gyrate, situated at the anterior third ; hinge heavy, the laterals distinct ; internal 

 margins strongly fluted. Length 4.0, height 3.5, diameter 2.75 mm. 



Exceptional specimens may reach a length of five millimetres, and some 

 specimens are shorter and higher than others. 



Venericardia ( Pleuromeris ) scitula n. sp. 

 PLATE 56, FIGURE 15. 



Uppermost Oligocene sands of Oak Grove, Santa Rosa County, Florida; 

 Burns and Aldrich. 



Shell small, much resembling the last species, but larger, more elevated, 

 and triangular, with twelve to sixteen low, broad ribs with narrower inter- 

 spaces, the ribs crossed by small, elevated, concentric threads or ridges, more 

 prominent distally than in the middle of the disk, and nowhere very conspicu- 

 ous ; lunule and escutcheon smooth, large for the size of the shell, the ribs on 

 the dorsal slopes smaller and feebler than those on the disk ; beaks small, high, 

 erect, nearly central. Length 5, height 5, diameter 4 mm. 



While in many respects similar to the last species, the differences seem to 

 authorize its separation specifically. 



Venericardia (Pleuromeris) tridentata Say. 

 Venericardia tridentata Say, Journ. Acad. Nat. Sci. Phila., v., p. 216, 1826 ; Binney's Say, 



p. 124, pi. xl., figs. 1-5, 1858 ; Dall, Bull. 37 U. S. Nat. Mus., p. 46, No. 183, 1889. 

 Cardita tridentata Say, Am. Conch., iv., expl. pi. xl., figs. 1-5, 1832; Conrad, Fos. Medial 



Tert, p. 76, pi. xliii., fig. 11, 1845; Am. Journ. Sci., 2d Ser., i., p. 404, 1846; Tuomey 



and Holmes, Pleioc. Fos. S. Car., p. 67, pi. xix., figs. 9, 10, 1855 ; Holmes, P.-Pleioc. 



Fos. S. Car., p. 31, pi. vi., fig. 8, 1858; not of Reeve, 1843. 



Cardita abbreviata Emmons, Geol. Rep. N. Car., p. 302, fig. 236, 1858; not of Conrad, 1841. 

 Venericardia (Cardiocardites) tridentata Meek, Checkl. Miocene Fos. N. Am., p. 7, 1866. 

 Pleuromeris decemcostata Conrad, Am. Journ. Conch., Hi., p. 12, 1867. 

 Actinobolus tridentata Conrad, Proc. Acad. Nat. Sci. Phila. for 1862, p. 578, 1863. 



Miocene of Wilmington, Magnolia, and the Natural Well, Duplin County, 

 North Carolina; Pliocene of the Waccamaw district, South Carolina; Coe's 

 Mills, Liberty County, and the Caloosahatchie River, Florida; Pleistocene of 

 Simmons Bluff, South Carolina, and the Florida coast in general ; recent from 



