360 UNITED STATES GEOLOGICAL SURVEY OF THE TERRITORIES. 



Generally, a few of these lines just below the suture are smaller and more 

 crowded than the others. 



1 know of oo shell very nearly allied to 1 his. As already stated in 

 connection with the generic description, it has much the general aspect of 

 Clave.Ua Vicksburgensis of Conrad, hut it presents well-marked and obvious 

 specific differences; while we have not the means of determining whether 

 or not that shell possesses the same generic characters as this. 



The specific name of this interesting shell was given in honor of my 

 friend George Scarborough, esq. (at that time a resident of Kentucky, but 

 now residing at Vineland, N. J.), who has been a devoted cultivator of geology 

 and other natural sciences for nearly thirty years past. 



Locality and position. — Butte au G res, on the Missouri River; in the 

 Fox Hills group of the Upper Missouri Cretaceous series. 



Fasciolaria (Piestocltiliis) Ciilbertsoni, M. &H. 



Plate :i->, tigs. 1, a, b, c, d, e,f. 



Fusits Culbertsoni, Meek and Hayden (1856), Proceed. Acad. Nat. Sci. Philad., VIII, 66.— Meek (1864), 



Smithsonian Check-List N. Am. Crefc. Fossils, 22. 

 Fusits Haydeni, Evans and Shumard (1857), Trans. St. Lonis Acad. Sci., I, 41. 



Fi s- 44 - Shell elongate-fusiform ; spire produced to nearly 



the length of the aperture and canal, acute at the apex; 

 volutions seven and a half, moderately convex, increasing 

 gradually in size ; those of the spire generally eacli pro- 

 vided wilh seven to nine obscure, or moderately distinct, 

 vertical folds, that are usually wanting on the last and 

 penultimate volutions; last or body volution not ventri- 

 cose around the middle, and tapering into the canal, 

 which is narrow, nearly straight, and rather long; aper- 

 ture narrow, lance-ovate in form, being acutely angular 

 above, and tapering gradually below; columella nearly 

 straight, but slightly twisted, and appearing as if entirely 

 destitute of plaits at the aperture, but provided with from 

 one to four farther up ; suture distinct; surface marked 

 by fine lines of growth, which are crossed by numerous, 



small, revolving lines, generally about equaling the linear furrows between. 

 Length about 2.22 inches; breadth, 0.67 inch; divergence of the apical 



angle, 26° to 30°. 



Fasciolaria (Piestochilus) 



Culbertsoni. 

 A broken specimen, 

 showing plaits of colu- 

 mella. 



