Fauna of the Buda Limestone. 17 



Locality. Shoal Creek, Austin, Texas. 



PLEUROPHORIDAE. 



Genus ARTICA Schumacher. 



ARTICA COMPACTA (White). 



PI. VII, tigs. 1, 2, 3. 



Pachymya ? compact a White, 1880, Proc. U. S. Nat. Mus., Vol. 



II, p. 297, PI. 6, ficjs. 3, 4. (Smithson. Misc. Coll., Vol. 19.) 



I'aclujmya * compacta White, 1883, Twelfth Ann. Eept. U. S. 



Geol. and Geog. Surv. Terr., Pt. I, pp. 22, 23, PL 17, 



figs. 4a, b. 



Dimensions, Length, 30nmi. : breadth, 19mm. ; thickness. 

 16mm. 



Original description. Shell small, narrower posteriorly than an- 

 teriorly, slightly gaping behind; beaks depressed, approximate, in- 

 curved, directed forward, their position being very near the front; 

 basal margin broadly convex; posterior margin narrowly rounded; 

 postero-dorsal margin forming an oblique downward and backward 

 truncation of that part of the shell; cardinal margin nearly straight, 

 subparallel with^ the basal margin, much shorter than the full length 

 of the shell; ligament short, its area depressed and sharply defined; 

 front very short, depressed beneath the beaks and narrowly rounded 

 below; umbonal ridges prominent and angular or subangular; the 

 space above and behind them, moderately broad and flattened; the 

 remainder of each valve somewhat regularly- convex. Hinge and 

 interior markings unknown. Surface marked by the ordinary con- 

 centric lines of growth. 



A study of the material found in the Buda, shows that this 

 shell is not a Pachymya, but either a Trapezium (Cypricardia), 

 as White suspected, or an Artica. The material that I have 

 been able to study indicates, by its hinge structure, that it be- 

 longs to the latter genus. 



Locality. Shoal Creek, Austin, Texas. 



CRASSATELLITIDAE 



Genus STEARNSIA White. 



STEARNSIA ROBINSI White. 



PL VII, fig. 7. 



tittarusia robins i White, 1887, Proc. Acad. Nat. Sci. Phila.. Pt. 

 1, for 1887, pp. 33, 34. PL 2, figs. J-9. 



