404 GEOLOGY OF THE IJLACK HILLS. 



lificulitcs oratKs Say, Am. Jour. Sci. and Arts, vol. ii, p. 41, 1821. 



Sa^e Creek uiid other places in the lihick Hills, Fort Pierre Group. 

 This and the above species are represented by numerous fra<rnients in the 

 collection, but it has been thought not desirable to illustrate either of the 

 species, as they have been so frequently g-iven by others. 



BacuUtcs ffrandis IT. & M., Moui. Am. Acad. Arts and Sci., vol. v, ii. ser., p. 402, I'l. 7, 



liK. I. 



Cheyenne River, Black Hills, Fort Pierre Group. 

 Baculifes nspera Morton, Synop. Org. Rem. Cret. Group U. S., j). 43, IM. 1, (ijjs. 12, l.{. 



A few fragments are present in the collection from the Fox Hills beds 

 at the eastern base of the Black Hills. 



Ancyloceras nncum (M. & H.) Meek, Piil. U. S. Geol. Surv. Terr., p. 400, IM. 21, fij;. 1, 

 ^ Ancyloceras {Hamites) uncum M. & H. 



South fork Cheyenne River, Black Hills, P'ort Pierre Group. 



Scapliitcs lamvformis M. & 11., Proc. Acad. Nat. Sci. Phil., \iii, 58; Meek, Pal. U. S. 

 Geol. Surv. Terr., p. 418, IM. G, fig. 0. 



Eastern base of Black Hills, Fort Benton Group. 



Scaphites conradi (Morton) ]\Ieek, Pal. U. S. Geol. Surv. Terr., p. 430, PI. 3(), fig. 2,^^ 

 Ammonites conradi Morton; f ScapliiteH pulcherrimns Ka'mer; Ammonites dance 

 D'Orb. ; and Ammonites nebracensis Oweu. 



Eastern base of Black Hills, Fox Hills Group. 



Flacenticeras placenta {^= Ammonites placenta De Kay aud others), see Pal. U. S. Geol. 

 Surv. Terr., p. 4G5, PI. 24, fig. 2. 



This species is well represented in the collection by some large indi- 

 viduals from the Black Hills, in bed No. 4. 



Heteroceras ? anyulatum (M. & H.) Meek, Pal. U. S. Geol. Surv. Terr., p. 484, PI. 21, tig, 

 Sf^Helicoceras angulattim M. & H. 



Head of south branch of the Cheyenne River, Black Hills, Fort Pierr^ 

 Group. 



