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 . txamitensis Cragin, but comparison with Cragin’s 
type, the equivalent of Aleek’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. 
PL 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 Rio. 
Localities. — Shoal Creek and Bouldin Creek, Austin, Texas. 
