1895.] NATURAL SCIENCES OF PHILADELPHIA. 51 



more or less corrugated concentrically towards the base, especially 

 posteriorly ; lunule in the larger specimens, very indistinct in the 

 smaller forms bordered by a well incised line. 



The surface markings resemble somewhat those of C. nuttalliopsis 

 Heilp.. but the anterior and posterior are too pointed, the shell in 

 general too inflated, and the umbonal angle too great for that species. 

 The larger specimens resemble M. californica Con. 



Localities. — Rio Grande at Webb-Zapata County line ; Smithville, 

 Bastrop Co., 2 miles east of Alto, Cherokee Co.; Mosley's Ferry, 

 Brazos Co. ; Cedar Creek, Robinson Co. ; Alum Bluff, Trinity River ; 

 Hurricane Bayou, Houston Co. ; Collier's Ferry, Brazos River, Bur- 

 leson Co. ; cutting on Houston East & West Texas R. R., 4 miles 

 north of Corrigan, Polk Co., Texas. Also from the base of the 

 bluff at Claiborne, Ala. 



Geological horizon. — Lower Claiborne Eocene. 



Types. — Texas State Museum. 



Genus TELLINA. 

 Tellina tallicheti nov. sp. PI. 3, fig. 1. 



Specific characterization. — Size and general form as indicated by 

 the figure ; not-twisted posteriorly ; thin ; posterior sub-biangulate ; 

 anterior rounded ; beak slightly behind the center ; lateral teeth 

 well developed ; posterior cardinal bifid ; pallial sinus and muscular 

 scars of good dimensions though rather dimly marked ; exterior 

 smooth, except a few concentric striae on the post- umbonal slope; 

 umbonal ridge passes from the beak to the posterio-basal margin. 



Locality. — Smithville, Bastrop Co., Tex. 



Geological horizon. — Lower Claiborne Eocene. 



Type. — Harris' collection. 



Genus SILIQTJA. 

 Siliqua simondsi nov. sp. P!. 3, fig. 2. 



Specific characterization. — Size and general form as indicated by 

 the figure ; anterior acutely rounded sub-basally, posterior rounded ; 

 from the umbo radiate two depressions (in the cast), the anterior deep, 

 the posterior more nearly vertical and faint ; pallial line and sinus 

 comparatively well marked. 



Locality. — Dr. Williams' quarry, Stephenson's Headright, Brazos 

 Co., Tex. 



Geological horizon. — Lower Claiborne Eocene. 



Type. — Texas State Museum. 



