8-' Cincinnati Society of Natural Histoiy. 



Cylherea, sj) ? (Cast.) 



Leda sp ? (Cast.) 



Tellina mooreana, Gabb. 



Leda media, Lea, 

 " compsa, Gabb. 



Pleurotona 2 sp. 



Rostellaria velata, Con. 



Turritella sp. 



Turbinolia pharetra, Lea. 

 From the "Green stone." 



Umbrella planulata. Con. 

 (A young specimen but not distinguishable from the Jackson form). 



Erato semenoides, Gabb. 



Agaronia punctulifera, Gabb . 

 • Corbula texana, Gabb. 



Neverita arota, Gabb . 



Phos texanus, Gabb. 



Limopsis declivis, Con. 



The occurence of the Jackson form of Umbrella in the strata 

 associated with forms heretofore supposed to be Claibornian is 

 certainly calculated to impress one with how little is known of the 

 distribution of the fossils of the Tertiary. 



IIL 



DESCRIPTIONS OF NEW SPECIES. 

 DOSINIA MERCENAROIDEA, n. Sp. 



Shell orbicular, moderately compressed, concentrically finely 

 striated, nearly smooth upon the umbo. Substance of the shell 

 thin, thickening towards the margins; lunule rather long and narrow 

 beak curved towards lunule, small and anterior to the centre; hinge 

 line rather long.' Teeth in left valve prominent, erect, central one 

 subtriangular. Ventral margin smooth. 



Length lA", Breadth \^-h'\ Thickness A" 



Locality: Upper landing at base of Claiborne Bluff. (My No. 

 9 bed Claiborne Section). 



This species is more rotund than the recent D. conccntrica 

 Gmel. and much thicker through the umbones. Only two speci- 

 mens found. 



