JR. T. Hill — Texas Section of American Cretaceous. 297 



Cross Timber (Dakota) beds in the Denison region, or, where 

 the latter are absent, as at Austin, owing to erosion or non-de- 

 position, directly upon the Comanche series, which demon- 

 strates their position to be in the middle, and not at the bottom 

 of the Texas Cretaceous as B. F. Shumard placed them. I 

 have verified by personal observations the occurrence of most 

 of the following forms in these shales at Austin and Eagle 

 Ford, and New Braunfels : 



Ostrea congesta. 

 Ostrea anomiaformis Roem. 

 Exogyra columbella Meek. 

 Lic-ina sublenticularis Shum. 



Lucina (Cyprimera) crassa 

 Meek. 

 Avicula irriclescens Roem. 

 Inoceramus mytilodes Mant. 



Roem. 

 Inoceramus 2^roblematicicsSch\ot 

 Inoceramus deformisM.. & H. 



Sca2mites sernicostatus Roem. 



" texanus Roem. 

 Ammonites percarinatus Meek 

 and Hall. 



* Ammonites qraysonensis Shum. 



* Ammonites Meekianus Shum. 

 Barbatia Shum. 



Area, sp. nov.? 



Anomia, sp. ind. 



And many fish remains. 



The relative position, identity of faunal and lithologic fea- 

 tures, and much stratigraphic data confirm the opinion pre- 

 viously expressed, that they are the equivalent of Meek and 

 Hayden's 2 and 3, or Niobrara and Benton. I believe them to 

 be the direct geographic continuation of the same geologic sedi- 

 ments, especially as seen by Newberry in northwestern New 

 Mexico, together with the underlying Dakota sandstone which 

 are represented by the Lower Cross Timber beds in northern 

 Texas. 



The contact of these shales with the over- and underlying 

 groups is beautifully displayed along the south banks of the 

 Colorado, opposite Austin ; and in the east bank of Shoal 

 Creek in the city itself, where there is a complete faunal and 

 stratigraphic break between the shales just as Meek observed 

 between the Pierre and Niobrara beds in the northwest and of 

 which it can truly be said here as he said of the same formations 

 there, that " the most strongly marked paleontological break in 

 the Upper Cretaceous section is at the line separating the 

 Niobrara from the Fort Pierre group, and that the beds above 

 this horizon represent the upper or White Chalk and those below 

 it the lower or gray chalk and perhaps also in part the Upper 

 Greensand of English geologists."* 



No equivalent of this division is found east of the Texas 

 region, only a few of the vertebrate fish remains, belonging to 

 species that have a wide geologic range, having been found in 

 the Gulf and north Atlantic regions. This fact adds confirma- 



* Cret. Pal., xlvi, xlvii.? 



