204 THE DEVONIAN AND CARBONIFEROUS. [bull. 80. 



by Marcou, and by Geinitz placed in part in the upper " Mountain 

 limestone," and in part in the Upper Coal Measures and the "Upper 

 Dyas n rocks of Marcou and Geinitz at Wyoming, Bennett's Mill, and 

 Nebraska City, with possibly the exception of C and D of the latter 

 place, belong to the horizon of the Upper Coal Measures. C and D 

 he thinks may be equivalent to the " Permo-Carboniferous " of the 

 Kansas section. 



All through this region the fossils of the Upper Coal Measures are 

 found either associated in the same stratum with those of Permian 

 type, or in strata intercalated between beds holding the other fauna ; 

 and the Coal Measure fauna becomes by degrees less conspicuous and 

 the Permian types more dominant on passing upward. Mr. Meek 

 maintains that the critical study of the fossils confirms the view pub- 

 lished by Hayden and himself in 1858 regarding the rocks of Nebraska 

 and Kansas, that — 



there is in this region a gradual shading off from an Upper Coal Measure to a Permian 

 fauna through a considerable thickness of strata forming a somewhat intermediate 

 group, which is called the " Permo-Carboniferous series :" also there is no defined break 

 between the intermediate series and the Permian above, or the Coal Measures below. 1 



He further adds : 



Under such circumstances it must be evident that all attempts to correlate partic- 

 ular unimportant beds here with minor subdivisions adopted in Europe, where a dif- 

 ferent state of things obtained, must necessarily fail. 



Mr. Meek recognized in his early studies in the section along the 

 Kansas River certain beds containing a fauna which he identified then, 

 in 1858, with the Permian, i. e.: Stratum 10 of the Cottonwood section. 

 Above this were some more or less Barren Measures of 100 to 200 feet 

 thickness, containing gypsum, followed by rocks of unmistakable Cre- 

 taceous age. In his early studies the rocks immediately below this 

 unmistakable Cretaceous bed he had, in conjunction with Mr. Hayden, 

 called "Permo-Carboniferous.'- This paper of 1867 which refers beds in 

 Nebraska to the Upper Coal Measures evidently considered only these 

 "Permo-Carboniferous" rocks of his early classification. The question 

 in dispute was as to whether the rock should be divided, making a Per- 

 mian system distinctly separate from the Carboniferous below. This 

 Meek positively objected to, his argument being that there was a gradual 

 mingling of the higher faunas with the Upper Coal Measure faunas, 

 and a gradual transition of the deposits from the lower horizon to the 

 upper without break, and without any marked change in paleontology 

 or lithology. 



Mr. Marcou, 2 in 1868, wrote that in Nebraska the u Dyas rocks" form 

 the bluffs on the Missouri River in the counties of Nemaha, Otoe, and 

 Cass. The rocks differ from those of the Carboniferous upon which 



they rest. They consist of clays of red, green, and blue colors ; of 



.^ . 



'Remarks on Professor Geintz's views respecting the Upper Paleozoic rocks and fossils of south- 

 eastern Nebraska. By F. B. Meek, Am. Jour. Sci., 2d ser., vol.44, 1867, pp. 338-339. 

 2 On the Dyas in Nebraska, by Jules Marcou. St. Louis Acad. Sci., Trans., vol. 2, 1868, pp. 562-5C4. 



