Fauna of the Buda Limestone. 13 



mens, are ornamented with two or three rows of tubercles; ribs 

 more elevated on the convex side of the shell; ventral margin 

 strongly dentate. 



The specimens collected from the Buda have not attained 

 such vigorous development as those from the Georgetown. 



Locality. Shoal Creek, Austin, Texas. 



PECTINIDAE. 



Genus PECTEN Mueller. 



PECTEN WRIGHTII (Shumard). 



PL I, fig. 4. 



Janira wrigktii Shumard, 1860, Trans. Acad. Sci., St. Louis, 



Vol. I, 1856-1860, p. 607. 

 Vola (Janira) wrightii Hill, 1889, Geol. Surv. Texas, Bull. No. 



4, p. 8. 



Vola wrightii Cragin, 1892, Fourth Ann. Kept. Geol. Surv. 

 Texas, p. 217, PL 32, figs. 2, 3. 



Dimensions. Length, 22mm. ; height, 28mm. 



Original description. Shell ovate, subtrigonal, longest diameter 

 from beak to base; superior valve flat or slightly concave, marked 

 with three strong, rounded, plications, which are prolonged at the 

 base into prominent angles; inferior valve strongly convex; anterior 

 and posterior slopes abrupt, margins straight and diverging from the 

 beak at an angle of about 40; surface ornamented with four very 

 prominent, simple radiating ribs or folds on the body of the shell, 

 and one much less developed within the margin on either side. Both 

 valves are also elegantly marked with crowded, strongly waved con- 

 centric, filiform striae; beaks elongated, slender, incurved; wings un- 

 known. 



Locality. -^Shosil Creek, Austin, Texas. 



SPONDYLIDAE. 



Genus SPONDYLUS Linna3us. 

 SPONDYLUS CRAGINI n. sp. 

 PL II, figs. 7, 8. 



Dimensions. Greatest length, 35mm. ; greatest breadth, 27mm. 

 Description. Shell variable, inequilateral, inequivalve, ob- 

 lique. Inferior valve the larger, ventricose, produced, orna- 



