6i St. Maurice and CivAiborne Pelkcypoda 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 pulcherrima Lea ; but there is no doubt in the 

 mind of the present writer that these 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 ^^xsplana, nor 

 wa.s\i\s pidcherrima quite old enough to begin to show the un- 

 dulations so characteristic of this species. 



Type.—l^o. 5998, Coll. Phila. Acad. (Lea Coll.) 

 Horizon a7id localities.— Cl^ihoruQ Eocene, Claiborne sands, 

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

 Specimens figured.— {Vigs. 14, 15) Cornell Univ. Paleont. 

 Coll. 



Ledatrumanin.sp., PI. 23. Figs. 18-19. 



Specific characterization.— Vorvii 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 by coarse, very sharply defined concentric 

 lines, abruptly ceasing with a slight nodular enlargement at the 

 umbonal ridge ; post-umbonal slope with two sharply defined 

 radiating nodular ribs, marking, with 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 p're-Claibornian pal- 

 eontological investigation in our Southern States. 



Type and specimens 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. 



