75 LiGNiTic Stage 75 



"Cabinet of the Academj'." 



This is one of the most abundant and chara(?leristic species of 

 our lower Eocene deposits both in the Gulf and Chesapeake em- 

 bankments. It presents a great many varietal forms in the Lig- 

 nitic and finally merges into T. cai'iyiata of the Claiborne Eocene. 

 We have noted in the American Journal of Science, vol. 47, p. 

 302-303, fig's. I, 2, 1894, the form or variety styled post-viortoni 

 from the Lignitic of Alabama (called carinata by de Greg.) char- 

 adlerized by comparatively faint spiral striation and by a sharp, 

 strong carina not so basally located as in the typical form. This 

 variety leads up to the form found in the Lower Claiborne beds 

 at Lisbon and elsewhere, and this in turn to the typical T. cari- 

 nata Lea. 



Lignitic localities. — Ala.: Tuscahoma; Nanafalia; Yellow bluff; 

 Bell's landing; Gregg's landing. 



Ga.: Ft. Gaines. 



Va.: Ratcliff wharf, Rapp. R.; Evergreen; 



Aquia creek; Potomac creek. 

 Md.: Ft. Washington. 



Specimens figiwed. — Fig. 3, Nanafalia; fig. 4, Bell's; Paleon- 

 tological Museum Cornell University. 



Turritella humerosa, PI. 10, fig'.s. 5, 6, 7. 



Syn. T. humerosa Con., (See Bull. Am. Pal., vol. i, p. 224). 



The more typical form is represented by fig. 5. Fig. 6 is 

 Whitfield's ninltilira and fig. 7 is Whitfield's airynome and also 

 pra(5lically Aldrich's bcllife7-a (Jr. Cinn. Soc. Nat. Hist., July 

 1885, p. 15c, pi. 3, fig. 13. See also Jr. Cinn. Soc. Nat. Hist., 

 ' July 1887, p. 81). The species is extremely variable in surface 

 marking, but there is no chance for drawing lines of .specific de- 

 marcation within its bounds. All shades of variation occur in 

 one and the .same bed. It ranks secondary iovwrtoni as a typical 

 lower Eocene species. 



Lignitic localities. — Ala.: Nanafalia; Tu.scahoma; Yellow bluff; 

 Bell's and Gregg's landings. 



Va.: Evergreen; Aquia creek; Potomac 



creek; Ratcliff wharf. 

 Md.: Ft. Washington. 



