Kansas, Oklahoma, New Mexico and Texas. 211 



With the Gryphwa Hm?neri zone, we have the beginning 

 of an important series of strata, containing a Lower Cretaceous 

 fauna well characterized and which can be subdivided into four 

 or five sub-fauna and easily followed and studied between Bel- 

 videre, Fort Washita, Fort Worth and Comanche Peak. 



We have three fades of the Lower Cretaceous or Neoco- 

 mian. One is called the Washita fades, composed mainly of 

 limestone and constitutes the true Washita division, as I estab- 

 lished it as long ago as 1853, when at Comet Creek, near Fort 

 Washita. The second fades is called by Professor Cragin 

 "Kiowa shales," being composed mainly of shales, instead of 

 the great development of limestone of the Washita fades. 

 The second fades has seemed until now to be confined to 

 the strata of Kansas. Then we have a third fades called 

 Fredericksburg division, at Comanche Peak, Walnut, Goodland 

 and further south. 



A great deal of confusion has been caused by a sort of dupli- 

 cation of one single series, the true Washita division, which 

 has been called in eastern and southern Texas Fredericksburg 

 division. A careful survey of all the strata composing the 

 Lower Cretaceous between Fredericksburg, Austin, Comanche 

 Peak, Fort Worth, Fort Washita and Comet Creek is much 

 needed. For it is plain that the Comanche Peak and Kiamitia 

 clay or Preston subdivisions are simply the base of the Washita 

 division, which cannot be separated from the Fort Worth 

 limestone. 



Therefore, instead of the classification used by Mr. Hill under 

 the single name of " Comanche series " or Lower Cretaceous, 

 composed of these divisions, 1st the Trinity, 2d the Fredericks- 

 burg, and 3d the Washita, we have the Jurassic series com- 

 posed of the Trinity and the Tucumcari division, and the 

 Lower Cretaceous or Neocomian composed of the Washita 

 division ; dropping the Fredericksburg, which is only a fades 

 of the Washita, and placing the Tucumcari division in its true 

 stratigraphic and paleontologic position. 



General tabular view for the whole country south of the 

 Arkansas River : 



Upper Cretaceous. 



Break. . 



f * « 



Neocomian 

 or 



Comprising all the subdivisions, as well 

 as the Kiowa and Fredericksburg fades. 

 Lower 1 t> ^ 1 Zone of the Gryphwa Kansana. 

 Cretaceous. ! • z ° ne of the Gryphcea Bcemeri. 



