18 
University of Texas Bulletin 
Astarta ( Stearnsia ) robinsi Hill, 1889, Texas Geol. Surv., Bull. 
No. 4, p. 11. 
Dimensions. — Length, 22mm.; breadth, 16mm. 
Original description — Shell much compressed, trihedral in marginal 
outline ; lunule long and narrow, nearly straight from end to end, concave trans- 
versely; escutcheon similar in shape and character to the lunule, but longer; 
beaks small, appressed, angular ; ligament slightly exposed, and it appears to 
have been divided into an outer and inner portion by a calcareous septum; um- 
bonal furrows distinct, producing an emargination at the posterior part of the 
convex basal border and. considerable prominence of the posterior extremity; 
hinge strong; the lateral teeth slender and extending the full length of the lu- 
nule and escutcheon respectively ; surface marked by strong concentric fur- 
rows and ridges, which end abruptly at the margin of the lunule and escutcheon 
respectively; the surface of both lunule and escutcheon plain. 
The material studied seems to be a little different from that 
figured by White, but a comparison with specimens from the 
Del Rio and a probable Georgetown rock, leads me to believe 
that the differences are not sufficient to be specific. 
Locality . — Shoal Creek, Austin, Texas. 
VENERIDAE 
Genus MERETRIX Lamarck. 
Meretrix leonensis ? (Conrad). 
PI. VII, fig. 4. 
Cytherea leonensis Conrad, 1857, Rep. U. S. and Mex. Bound. 
Surv., Vol. I, Pt. 2, p. 153, PL 6, fig. 1. 
Cytherea leonensis Hill, 1889, Texas Geol. Surv., Bull. No. 4, 
p. 14. 
Dimensions. — Length, 35mm.; breadth, 44mm. 
Description . — Shell medium, subovate, inequilateral, moder- 
ately ventricose; beaks, about one-fourth the length of the shell 
from the anterior end, small, excavated anteriorly, approximate. 
Anterior margin slightly curved, rounded below; ventral margin 
broadly rounded; posterior margin convex, rounded below. Sur- 
face ornamented with concentric lines of growth. 
The material found in the Buda resembles C. leonensis, as 
figured in the Mexican Boundary Report. However, the anterior 
margin seems to be more gently curved in my specimens, while 
