98 Bulletin 31 98 



powerful ; exterior surface ornamented with strong and closely set lines of 

 growth, which transverse the entire shell, becoming, however, less prom- 

 inent on the umbonal slope. 



Length of the shell about an inch and a quarter, slightly exceeding 

 the height. 



We have already remarked in the Academy's Proceedings : 

 "This is certainly very distinct from antestriata. Besides the 

 points of difference mentioned b}'^ Heilprin the following may be 

 noted : The umbonal ridge is much sharper in texana, and there 

 is a trace of a sinus just below it ; the posterior margin is not sub- 

 biangular as in antestriata, and the valves are less oblique." 



'^Vrova trapaquara this species can be distinguished by its 

 surface markings, lower form, and the depression just below the 

 umbonal ridge." 



Type. — Apparently lost. 



Horizon. — St. Maurice Eocene. 



Specimen Jigured. — Tex. State Museum (Univ.). 



Localities. — Near McBee's schoolhouse, 2 miles E. of Alto, 

 Cherokee Co. and Berryman's land, all in Cherokee Co. ; Murch- 

 ison's Headright and Eively's Place, Houston Co., Tex. ; H. 

 Johnson's Place, Miss. Casts and imprints of what may be a 

 variety of this species are found at Eutaw Springs and Vance's 

 Ferry, S. C. 



Crassatellites antestriatus Gabb, PI. 34. Figs. 2, 3. 



Crassatclla antestriata Gabb, Jr. Phila. Acad., Nat. Sci. , vol. 4, i860, 

 p. 388, pi. 67, fig. 53. 



Crassatella antestriata Har. , Proc. Phila. Acad. Nat. Sci., 1895, p. 

 49, pi. I, fig. 10, 10, a. 



Gabb^s original description. — Subquadrate ; beaks very small ; um- 

 bonal slope^wide, umbonal ridge rounded ; anterior margin semicircular ; bas- 

 al regularly arcuate, posterior sub-biangular ; surface marked by numerous, 

 large, transverse folds, which commence at the anterior margin, but dis- 

 appear before reaching the middle of the shell, leaving the rest almost per- 

 fectly smooth, (this is not the result of attrition); interior margin very del- 

 icately crenate, anterior muscular impression semilunar, posterior subquad- 

 rate. 



Dimensions. — Length .5 in., width .6 in. 



As was noted in our Phila. Acad, article "Gabb's figure and 

 description were of a young specimen ; the figure herewith given 



