DESCRIPTION OF SPECIES. 

 MOLLUSCA. 



PELECYPODA. 

 ARCIDAE. 



Genus BARBATIA Gray. 



BARBATIA SIMONDSI n. sp. 



PL I, fig. 6. 



Dimensions. Length, 55mm. ; breadth, 32mm. 



Description. Shell medium, elongate, inequilateral; beaks 

 near anterior end, inflated, directed forward; anterior margin 

 short, rounded; ventral margin nearly straight; posterior mar- 

 gin rounded, slightly truncate above ; dorsal margin subparallel 

 to the ventral; side of valve with a depression extending from 

 the beak obliquely backward and downward to the ventral mar- 

 gin; surface marked with concentric lines of growth crossed by 

 fine, well pronounced, radiating striae, which cover the entire 

 surface of the shell. 



This shell resembles Area galliennei d'Orbigny, but it is 

 slightly different in form, and the striae do not alternate in 

 size. It also resembles Barbatia micronema Meek and Area gal- 

 liennei var. trarmtensis Cragin, but comparison with Cragin's 

 type, the equivalent of Meek's species, shows that the form and 

 markings are somewhat different. 



Localities. Barton Creek and Shoal Creek, Austin, Texas. 



PINNIDAE. 



Genus PINNA Linnaeus. 



PINNA sp. 

 PI. I, fig. 3. 



Description. There are, at hand, two specimens of this spe- 

 cies, but both are too fragmentary for description. The specimen 

 figured was found near the contact of the Buda with the Del Bio. 



Localities. Shoal Creek and Bouldin Creek, Austin, Texas. 



