139 St. Maurice; and Ci.aiborne Pelecypoda 129 



ferred by most authorities to 7iana. But the concentric striation 

 is not coarser than in imgnlina, 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 unguliyia in hand while describing this species. 

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

 of the shell not generally shown in young ungnlina ; 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- 

 phery of the shell suggesting perhaps an epidermis as referred to 

 by Dall under Felaniella. We have no specimens at all compar- 

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



7)//^.— 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. 



Specimens 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, pi. i, fig. 18. 



Lucina [Sphcsrella) t(svis\a.r. paruminflata de Greg. , Mon Faun. Eoc. 



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

 Diptodonta 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.— 1^0. 5088, Lea Coll., Phil. Acad. 



