65 St. Maurick and Claiboiine Pelecypoda 65 



Leda bella and plicata Dall, Trans. Wag. &c, '95, III, p. 578. 



Conrad's original description. — Shell ovate, elongated, rostrated, 

 with numerous regular concentric striae, and two carinal lines on the anter- 

 ior submargin diverging from the apex : on the posterior side is a slight fur- 

 row from the apex to the base, length, half an inch. 



Locality. — Claiborne, Ala. lyondon clay. 



This species is at once distinguished from media by its coarser, 

 continuous Hues of growth, more anterior beaks, less conspicuous 

 swelling between the siphons, its greater rarity, less inflation and 

 lack of any serration of post-umbonal radiating ridge. Our spec- 

 imens do not show the anterior, radiating depression so plainly as 

 does Lea's type. Some specimens, especially from the Orange- 

 burg district, show a slight swelling along the posterior basal 

 margin. Young, thin specimens show an interior radiating 

 ridge, from beak to posterior end (as per fig. 14). Old, thick- 

 ened specimens show a vertically striated, minute, triangular area 

 beneath the hinge teeth, just in advance of the cartilage (fig. 13). 



7y/>(?.— Conrad Coll., Phila. Acad. 



Horizon. — Claibornian and St. Maurice Eocene. 



Speciviens figured. — Paleont. Coll. Cornell Univ. 



Localities.— Claiborne, Ala. Six mile W. N. W. of Orange- 

 burg, S. C. Marble Q'y, Hammett's Branch, L,a. 



Leda pistorupes, n. sp., PI. 24. Figs. 17,18. 



Specific characterization. — Size and general form as indicated 

 by the illustrations and explanations ; rather thin ; marked about 

 the umbo and base by moderately fine concentric lines, but med- 

 ially by three or four folds on which are engraved almost micro- 

 scopic, very regular, concentric striae ; posterior radii arranged 

 somewhat as in bella, but with obvious raised concentric, sharp 

 folds ; interior very much as in bella though naturally showing 

 marked concentric undulations. 



Types — Aldrich's collection, Birmingham, Ala. 



Horizon . — Claiborne stage . 



Locality. — Baker's Bluff, Tombigbee River, Ala. 



Leda media Lea, PI. 25. Figs. 1-4. 



Nucula media L,ea, Cont. to Geol. 1833, p. 83, pi. 3, fig. 62. 



