464 GEOLOGY OF THE BLACK HILLS. 



Baculites ovatus Say, Am. Jour. Sci. and Arts, vol. ii, p. 41, 1821. 



Sage Creek and other places in the Black Hills, Fort Pierre Group. 

 This and the above species are represented by numerous fragments in the 

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

 species, as they have been so frequently given by others. 



Baculites grandis H. & M., Mem. Am. Acad. Arts and Sci., vol. v, n. ser., p. 402, PI. 7, 

 fig. 1. 



Cheyenne River, Black Hills, Fort Pierre* Group. 

 Baculites aspera Morton, Synop. Org. Eem. Gret. Group U. S., p. 43, PI. 1, figs. 12, 13. 



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

 at the eastern base of the Black Hills. 



Ancyloceras uncum (M. & H.) Meek, Pal. U. S. Geol. Surv. Terr., p. 409, PL 21, fig. 1, 

 = Ancyloceras (Samites) uncum M. & H. 



South fork Cheyenne River, Black Hills, Fort Pierre Group. 



Scaphites larvceformls M. & H., Proc. Acad. Nat. Sci. Phil., viii, 58 ; Meek, Pal. U. S. 

 Geol. Surv. Terr., p. 418, PI. 6, fig. 6. 



Eastern base of Black Hills, Fort Benton Group. 



Scaphites conradi (Morton) Meek, Pal. U. S. Geol. Surv. Terr., p. 430, PI. 36, fig. 2, = 

 Ammonites conradi Morton ; f ScapMtes pulclierrimus Eoenier ; Ammonites danw 

 D'Orb. ; and Ammonites nebracensis Owen. 



Eastern base of Black Hills, Fox Hills Group. 



Placenticeras placenta (= Ammonites placenta De Kay and others), see Pal. U. S. Geol. 

 Surv. Terr., p. 465, 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. 



Eeteroceras ? angulatum (M. & H.) Meek, Pal. U. S. Geol. Surv. Terr., p. 484, PI. 21, fig. 

 3, = Helicoceras angulatum M. & H. 



Head of south branch of the Cheyenne River, Black Hills, Fort Pierre* 

 Group. 



