73 St. Maurice and Claiborne Pelecypoda 73 



This form we have heretofore regarded as but a large well 

 developed claibornensis. It is a ver}' widel}' distributed St. 

 Maurice species, varj'ing considerably, however, from state to 

 state as traced from Mexico to the Carolinas. It is most abund- 

 ant and typically developed just below the ferry at Claiborne, 

 Ala., but is rarely found in a perfect state of preservation. It 

 is common also at Lisbon and Hamilton Bluff. 



The extent of striation upon the surface varies greatly even 

 at the tj^pe locality. Sometimes the incremental lines cover 

 nearly the entire surface. At Vivian, La., a more nearly equi- 

 lateral form occurs, with .stronger striae, var. viviayiensis (fig. 31); 

 and 5 miles N. and N. W. of Orangeburg casts showing undula- 

 tions (fig. 30) are not rare. We have called the latter var. 

 orangeburgensis though they ma\" belong to quite a distinct 

 species. 



Type. — U. S. Nat. Museum. 



Horizo7i. — St. Maurice Eocene. 



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

 fig. 28, from U. S. Nat. Mus. 



Localities. — Smithville, Mosley's Ferry, Cedar Cr., Tex. 

 Noble's Ldg., Roselawn, St. Maurice, Calvin, i mile S. of the 

 "Marble Q'y", Chautauqua, La. From Hamilton Bluff to the 

 Upper bluff at Claiborne, Ala. Kitt's Ravine, S. C. 



In varietal forms at Vivian, La. and 5 miles N. and N. W. 

 of Orangeburg, S. C. 



Nucula magnifica Conrad, PI. 26. Figs. 1-3, 8. 



N. magnifica Con., Foss. Shells Tert. Form., 1833, p. 37. 

 A', sedgwickii Lea, Cont. to Geol., 1833, p. 79, pi. 3, fig. 58. 

 A^ magnifica d&Gve^., Mon. Faun. Eoc. Ala., 1892, p. 189, pi. 22, 

 figs. 16-19. 



Conrad^ s original description. — Shell obliquely subtriangular, very 

 inequilateral, smooth, thick, with obscure reticular striae ; anterior side 

 truncated ; posterior side elongated or cuneiform ; basal margin crenated ; 

 hinge teeth elongated ; within pearly or purplish. Length nearly % of an 

 inch. Locality, Claiborne, Ala. Cab. Acad. N. S. 



So far as w^e have observed typical magnifica occurs onl}'' in 

 the Claiborne sand at Claiborne and nearbv localities. The um- 



