CRETACEOUS FOSSILS. 423 



the powdery portion, the impression of a distinct fold, very oblique in its 

 direction, was revealed, the existence of which removes the species from 

 the genus to which it has been referred, and proves its close Jurassic rela- 

 tions to F. (C.) fusiformis H. & M. The specimens under consideration 

 appear a little more slender than the figures given by Mr. Meek, he cit , 

 but the presence of the shell on his specimens will readily account for this 

 seeming difference. 



Formation and locality. — In limestones containing a mingling of the 

 fossils of Nos. 4 and 5 of the Cretaceous formations of this region, on Old 

 Woman Fork of the Cheyenne River, Wyoming. 



FASCIOLAEIA (PIESTOCHEILTJS) CULBERTSONI. 



Plate 12, fig. 11. 



Fusus culbertsoni M. & H., Proc. Acad. Nat. Sci. Phil., vol. viii, p. 66. 

 Fusus culbertsoni (M. & H.) Meek, Smithsonian Check List Invert. Foss., p. 22. 

 Fusus haydeni (Evans & Shum.) Meek, Pal. U. S. Geol. Surv. Terr., p. 360. 

 Fasciolaria (Piestochilus) culbertsoni (M. & H.) Meek, Pal. U. S. Geol. Snrv. Terr., p # 

 360, PI. 32, 1. 



Shell attaining rather more than a medium size, elongate-fusiforme ; 

 spire produced and slender ; aperture elongate, much lengthened below ; 

 volutions moderately convex below the middle and appressed in the upper 

 part and below the suture ; columella straight, slightly thickened. Surface 

 marked by numerous elevated revolving striae, generally, but not always, 

 with flattened interspaces, and crossed by strong transverse strise of growth, 

 which have a broad ventral curvature in crossing the appressed upper part of 

 the volution, and are then directed forward, with a broad curve, across the 

 swell of the volution ; below this they are directed parallel to, and along 

 the anterior rostration. 



The specimens of this species in the collection are imperfect, and do 

 not afford material for a full description. The number of volutions cannot 

 be made out, nor can the entire features of the columella be seen. Mr. F. 

 B. Meek states that the columella has an obscure fold in the upper part, 

 which our specimens, although much larger than any figured by that author, 

 show no evidence of. 



