57 LiGNiTic Stage 57 



Nassa ( ) exilis, PI. 7, fig. 9, 



S\-n. Simpuliim [Epidroiiius) e.vilis Con., Jour. Acad. Nat. Sci. Phila., 



vol. 4, p. 293, pi. 47, fig. 31, i860. 

 Triton exilis Aid., Geol. Surv. Ala., Bull, i, p. 56, 1S86. {''Nassa 



cancellata''' ?). 

 Triton eA-ilis de Greg., Mon. Faun. Roc. Ala., p. 98, pi. 7, fig. 44, 



1890. 

 Cominella ? interanda Cossm., Ann. Geol. and Pal., 1893, p. 34. 



Conrad's original description. — "Elongated ; whorls seven, 

 rounded ; ribs longitudinal, numerous ; revolving lines fine and 

 raised, eleven or twelve on the penultimate whorl : body whorl 

 striated to the base ; spire much longer than aperture ; columella 

 plain and obtusely carinated at ba.se ; labrum striated within ; 

 peristome sinuous. Length ^ inch." 



Some forms of this species, especially when the lower end of 

 the columella has been broken off or eroded — which frequently 

 happens — resemble closely N. caiicellata Lea. Yet when ex- 

 amined under a hand glass these accidental features are readily 

 detected ; and I yet have to find any specimens of cancellata 

 in Lignitic beds. De Gregorio correcflly remarks : "la figure de 

 Conrad laisse a desirer. " Cossmann was perplexed at a 

 specimen of this species sent him from Gregg's by Meyer under 

 the name of Buccinum sagenuvi, and referred it to one of De 

 Gregorio' s many species, i. e. to interanda. He was again 

 perplexed as to its generic position, referring it to Cominella 

 with a query. 



That this is not far from Nassa cancellata is evident from 

 Hatchetigbee specimens which are shorter, coarser ribbed, and 

 with columnar features not so sharply defined as in typical 

 exilis. 



Localities. — Alabama : Gregg's landing ; four miles above 

 Hamilton bluff on Alabama river ; Hatchetigbee bluff. 



Type. — Doubtless in Acad. Nat. Sci. Phila., though I fail to 

 find reference to it in my notes. 



Specimen Jigtired. — From Gregg's landing ; now in the 

 Paleontological Museum, Cornell University. 



