308 R. T. Hill — Texas Section of American Cretaceous: 



While the upmost strata of the Washita division have many- 

 species characteristic of the lower Middle Cretaceous of Europe,* 

 I believe that there is no room to doubt that the deep marine 

 fauna of the whole of the Comanche series shows a wonderful 

 similarity to well-known forms of the European strata below 

 the upper portions of the Middle Cretaceous, and bearing spe- 

 cial resemblance, in its lower portion, to the Neocomian. The 

 presence of Middle Cretaceous forms in the upper portion of 

 the Washita division, near its transition into the Dakota sand- 

 stones, is confirmatory of Meek's opinion that the latter could 

 not have been older than the upper portion of the Middle 

 Cretaceous. Not only is the Comanche series older, but the 

 faunal and stratigraphic breaks between it and the Upper 

 Cretaceous are complete, and show in this a great similarity to 

 the European Cretaceous, where, according to Etheridge, " of 

 the total number of fossils from the 'Lower Greensand ' or 

 Upper Neocomian (upwards of 400) only 65 (or 16 per cent) 

 pass to the Upper Cretaceous (chiefly to the Gault). This 

 paleontological break with unconformity between the Lower 

 Greensand and the Gault in the south of England, and the top 

 of the Speeton clay and succeeding Red chalk or Hunstanton 

 limestone in Norfolk, clearly show that a definite boundary 

 line exists between the lower and upper parts of the Cretaceous 

 system of England." 



Dr. Ferdinand Roemer, after having accepted the erroneous 

 stratigraphic theory, pointed out in the previous pages, that 

 this series rested upon the Upper division, instead of uncon- 

 formably beneath it, endeavored to make the paleontology fit • 

 this hypothesis, much to the obscuration of our Cretaceous 

 geology. From the foregoing evidence, I believe there is 

 room to doubt the correctness of bis opinion that "the Cre- 

 taceous strata of Texas altogether belong to the Upper Chalk, 

 i. e., the chalk above the Gault, and indeed so much so that 

 they correspond to the horizon of the White Chalk ( l Etage 

 Senonien,' D'Orbigny), and to the upper part of the Chloritic 

 Chalk ('Etage Turonien,' D'Orbigny) of Europe; but, in ad- 

 dition, include the lower or Neocomian. "f 



I have used the three divisions which a fortunate series of 

 non-conformities have displayed at Austin, for the purpose of 

 clearer contrast, but farther north in the Fort Worth and 

 Denison region the sediments are more continuous from the 

 first approach of the Mesozoic seas upon the Carboniferous 

 continent as seen in the Dinosaur sands to the Marine Tertiary. 

 This section reveals two transitions from littoral deposits of 

 sands to deep-sea chalks and back again, the shallows of the 

 Dakota (Lower Cross Timber) sands representing the medial 



stage. 



* Juronien, of D'Orb. f Kreid. von Texas, p. 25. 



