129 St, Maurice and Claiborne Pelecypoda 129 



f erred b}- most avithorities to naiia. But the concentric striation 

 is not coarser than in luigulhia, the shell substance is rather 

 thick and the muscular scars are well-defined. These latter fea- 

 tures differing from Lea's description show he must have had 

 samples of young U7io^ulina in hand while describing this species. 

 lu a few specimens, like those figured there is a certain obliquity 

 of the shell not generally showaa in young nngulina ; also 

 the strong, apparently adult bifid character of the pos- 

 terior cardinal in the right valve contrasts rather strongly 

 with the narrow, often simple representative in ungulina. 

 There is almost a scaly, knife-edge sharpness about the peri- 

 pher}' of the shell suggesting perhaps an epidermis as referred to 

 b}^ Dall under Felaniella. We have no specimens at all compar- 

 able with Lea's in size, 34^ inch in diameter ! 



Type. — Probably No. 5142, Lea Coll., Phila. Acad., but 

 there is considerable doubt in the matter as shown by Lea's de- 

 scription . 



Horizon. — Claiborne Eocene. 



Speci7nens figured. — Paleont. Mus. Cornell Univ. 



Locality. — Claiborne, Ala. 



Diplodonta inflata Lea, PI. 40. Figs. 17-19. 



Egeria inflata Lea, Cont. to GeoL, 1833, p. 50, pL i, fig. 18. 



Lucina '\Sphcerella)lcevisvax. paruuiinflata de Greg., Mon Faun. Eoc. 



Ala., 1890, p. 207, pi. 29, figs. 16-17. 

 Diplodonta sp. Harris. These Bulletins, vol. 2, p. 257, pi. 19, fig. 7. 

 D. inflata Dall, Trans. Wag., Ill, 1900, 1182. 



Lea'' s original description. — Shell subrotund, rather transverse, 

 inflated, subequilateral, very finely and concentrically striate, sub- 

 stance of the shell very thin ; beaks rather elevated ; posterior slope fur- 

 nished with an indistinct fold. Cicatrices scarcely perceptible ; cavity of 

 the shell much excavated, of the beaks deep and rounded, margin entire. 



Diam. .2, Length 7-20, Breadth 7-2oths of an inch. 



As Dall remarks this shell is never really much "inflated". 

 Hence Gregorio's variety. 



This species has a more squarish form, is thinner and is far 

 more rare in the Claiborne sand than ungulina. 



Type.—^o. 5088, Lea Coll., Phil. Acad. 



