74 BUI^LETIN 31 74 



bonal region seems heavy, deep, inturning, when compared with 

 the same parts of individuals from the St. Maurice Stage (var. 

 viauricensis, n. var., figs. 4-6). Compare pi. 26, figs. 2 and 3 

 with fig. 4. Also note that the width of fig. 8 is to its height as 

 I : 2.3. The typical older, or inauricensis variety as here figured 

 is found at the base of the bluff just above the Upper Landing at 

 Claiborne and at Lisbon, in Alabama and westward into Texas. 

 Likewise in the Orangeburg District of South Carolina, though 

 there, as usual, a tendency is shown to assume something of a 

 true Claiborne aspect. 



Type. — Phila. Acad. Nat. Sci. 



Horizon. — Claiborne and St. Maurice Eocene stages. 



Specimens figured. — Paleont. Mus., Cornell Univ. 



Localities. — Texas (where according to my MS report to the 

 Texas Survey, 1893, "The specimens have slightly less conspic- 

 uous beaks, the center of the lunule is slightl}' more elevated and 

 the lunule is shorter than in the specimens from Claiborne' ' ) : 

 Devil's Eye, Col. Riv. ; Col. Riv. just below the mouth of Alum 

 Cr. ; Smithville ; Little Brazos River, Mosley's Ferry road ; Bra- 

 zos River 500 yards below the mouth of Little Brazos River ; 

 Cedar Creek, S. E. Cor. Wheelock League ; Elm Creek, Lee Co. ; 

 Campbell's Creek, Robertson Co. ; Sabine River. Louisiana : 

 Sabine River ; Hammett's Branch ; Monroe well ; Columbus, 

 Noble's Landing, Ouachita River. Alabama : Coffeeville ; Lis- 

 bon ; base of Claiborne Bluff ; Claiborne sands. South Carolina : 

 3 and 6 miles W. N. W. of Orangeburg ; 5 miles N. of Orange- 

 burg. North Carolina : 1 7 miles above Newbern on the Neuse 

 River. 



Nucula ripae, n. sp., PI. 26. Figs. 9-10. 



Specific characterization. — Form and size as indicated by the 

 figures and explanations ; surface covered with fine, somewhat 

 irregular lines or small folds of growth ; lunular and escutcheon 

 areas broad, with margins of the valves raised or pouting ; no 

 sharpl}' defined radiating lines on these areas separating them 

 from the general surface of the valves, the definition being 

 brought about by fairly well defined obtuse, radiating ridges ; 



