16 CARBONIFEROUS AMMONOIDS OF AMERICA. 



subcavum Miller and Gurley, Schistoceras niissouriense Miller and Faber; in 

 Kansas, ^'Goniatites" parvus Shumard; in Texas, Goniolohoceras icelleri 

 Smith, Dimorplioceras texanum Smitli, Agathiceras ciscoense Smith, Popano- 

 ceras ganti Smith, Shumardites simondsi Smith, Schistoceras hildrethi Morton, 

 8. Jii/atti Smith, Gastrioceras globulosum Meek and Worthen, G. subcavum 

 Miller and Gurley, Schuchertites grahami Smith. All these Texas species 

 came from Graham, in the Cisco formation, associated with a typical 

 Upper Coal Measures fauna. Many of the other species are identical with 

 forms in the Uralian formation, but the numerous ammonites are more 

 highly developed than any known in the European Upper Coal Measui'cs; 

 the nautiloids found in the Graham beds are mostly identical with forms 

 that also occur in the overlying Wichita Permian, as are also most of the 

 other invertebrates. But the stratigraphic position is about 1,000 feet 

 below the Wichita beds, in a region where the structure is exceedingly 

 simple, the strata being nearly horizontal, thus precluding the possibility 

 of a mistake in the stratigraphy. 



Permian. — Ammonoids are at present known in tlie American Permian 

 only in Texas, in Wichita, Bayloi', Archer, and Kent counties. The geo- 

 logical survey of Texas I'ecognized two divisions of this group : (1) Tlie 

 Wichita and Clear Fork beds, from which Dr. C. A. White" described 

 the following foruis : Paralegoceras bai/lore)/se White, Popanoceras ivalcotti 

 White, Waagenoceras cummins'i White, MedUcottia copei White ; (2) the 

 Double Mountain beds, from which only a single ammonite is known, 

 Waagenoceras hilli Smith, described in this paper. 



The Wichita beds are generally correlated with the Artinsk stage of 

 Russia, the Fusulina limestone of Sosio in Sicily, and the Middle Productus 

 limestone of India, some of the ammonite species being very nearly 

 related in all these localities. 



The Double Mountain beds are probablv Upper Permian, and should 

 be correlated with the Hungarites beds of Djulta in Armenia and the 

 Upper Productus limestone of India; but this is purely stratigraphic, the 

 known fauna of the Upper Permian of Texas being too scanty to warrant 

 paleontologic correlation. 



"Bull. U. S. Geol. Survey No. 77, 1891. 



