48 PROCEEDINGS OF THE ACADEMY OF [1895. 



Geological horizon. — Lower Claiborne Eocene. 



Locality. — Brazos River, Tex., one and one-half miles below 

 Mosley's Ferry. 



Genus VENERICARDIA. 

 Venerioardia trapaquara nov. sp. PI. 1, fig. 7. 



Specific characterization. — General form as figured ; ribs about 

 twenty- four, compound, i. e. , broad at base, surmounted by a medial 

 dentate carina; umbonal ridge prominent. 



This species is remarkable for its quadrangular form and. the 

 prominence of its umbonal ridge. It belongs to the alticostata stock 

 and is most nearly allied to Cardita subquadrata Con. (Jr. Ac. Nat. 

 Sci. Phila., 2d Ser., 1848, p. 128, pi. 14, fig. 10), but from Conrad's 

 description and figure it is evident that his species is much more 

 compressed, the umbonal ridge less prominent, and the beaks more 

 nearly central. 



Locality. — Cedar Creek, southeast corner of Wheelock League, 

 200 yds. north of Brazos Co. line, Robertson Co. , Tex. 



Geological horizon. — Lower Claiborne Eocene. 



Type. — Texas State Museum. 



Genus ASTARTE. 



Astarte smithvillensis nov. sp. PI. 1, figs. 8, a; 9, a, b, c. 

 A. conradi Buckley, 1st Ann. Rep. Geol. Agr. Surv. Tex., 1874, p. 63. 

 Crassatella alta (young) Heilp., Cont. to Geol., 1884, p. 38. 

 Astarte tellinoides Heilp., Proc. Ac. Nat. Sci. Phila., 1890, p. 402. 



Specific characterization. — Size and general form as indicated by 

 the figures ; surface in typical specimens marked by strong concen- 

 tric rugae especially towards the base; these slope gently above but 

 abruptly below and are superimposed by fine striae; umbones flat- 

 tened. 



This species shows great variations in form and size as well as 

 markings. At Collier's Ferry some specimens are more elongated, 

 others more rotund ; some have crenulations on the interior submar- 

 gin while others are smooth. Several of these forms are shown by 

 the figures cited. 



Localities of the typical jorm. — Devil's Eye, Colorado River, 

 Bastrop Co.; Smithville, Bastrop Co., Tex. 



Locality of the smaller forms. — 15 miles southeast of Nacog- 

 doches, Nacogdoches Co., Tex. 



Geological horizon. — Lower Claiborne Eocene. 



Types. — Texas State Museum. 



