6i St. Maurice and Claiborne Pelecypoda 6i 



rare. Among various Ledas submitted to us for study by Hon. 

 T. H. Aldrich were two specimens (figs. i6, 17) labelled appar- 

 ently correctly pnU/i err/ //m Lea ; but there is no doubt in the 

 mind of the present writer that the.se are simply the young of 

 plana. They are from typical Claiborne at Baker's Bluff, Ala. 

 Lea did not see the umbonal or earlier portions of his plan a, nor 

 vcashis p///r/ierr//na quite old enough to begin to show the un- 

 dulations so characteristic of this species. 



T}'pe.—No. 5998, Coll. Phila. Acad. (Lea Coll.) 

 Horizon and localities. — Claiborne Eocene, Claiborne sands, 

 Claiborne, Ala. ; 17 miles above Newbern, Neuse River, N. C. 

 Specimens figured. — (Figs. 14, 15) Cornell Univ. Paleont. 

 Coll. 



Leda trumani n. sp., PI. 23. Figs. 18-19. 



Specific characterization. — Form and general dimensions 

 about as represented in the illustrations (though more pointed 

 posteriorly as that portion is broken off in the specimen figured) ; 

 general .surface marked b)^ coarse, very .sharply defined concentric 

 lines, abruptl}' ceasing with a slight nodular enlargement at the 

 umbonal ridge ; post-umbonal slope with two sharply defined 

 radiating nodular ribs, marking, wath the row of nodules men- 

 tioned above, the limits of two concave, radiating interspaces the 

 lower of which is horizontally, finely striate, the upper with ob- 

 lique lines increasing in strength upwards ; escutcheon and lunu- 

 lar spaces each with a pair of simple rays radiating from the beak 

 and recurving into the hinge line half way to either extremity 

 (.see fig. 19). 



Named in honor of Hon. Truman H. Aldrich whose interest 

 in Eocene mollusca practically inaugurated pre-Claibornian pal- 

 eontological investigation in our Southern States. 



Type a7idspecime?is figured. — Deposited, Pal. Museum, Cor- 

 nell Univ. 



Horizon and localities. — St. Maurice Eocene. Base of Clai- 

 borne Bluff ; Hamilton Bluff, Ala. Three and six miles W. N. 

 W. of Orangeburg, S. C. Ft. Gaines, Ga. 



