504 R. T. HILL THE COMANCHE SERIES. 



attemptiDg a minute correlation of its numerous horizons with any beds of 

 the eastern hemisphere, it has been conceded generally that at least the 

 upper portions of this series are of lower Cretaceous age because of their 

 clearly defined stratigraphic position unconformably beneath the Dakota sands, 

 which all authorities have conceded to be of Cenomanian affinities ; a con- 

 clusion strengthened by the striking paleontologic resemblance of the whole 

 upper Cretaceous (or Meek and Haydeu Cretaceous) series to that of Europe. 

 The lower beds of the Comanche series have affinities which entitle them to 

 comparison with the upper Jurassic, while the upper beds have Neocomian 

 and Cenomanian resemblances. The Comanche series as a whole, however, 

 presents great paleontologic evidence at variance with every European stand- 

 ard, and it is premature to make paleontologic correlations with it. In this 

 paper I shall endeavor to clearly define this series stratigraphically, and 

 leave for others the discussion of the faunal resemblances and diffijrences. 



The main area of the Comanche series extends from western Arkansas 

 through southern Indian territory to the meridian of 97° 30^ thence south- 

 ward and southwestward across Texas to New Mexico, a distance of more than 

 1,000 miles, and then southward indefinitely into Mexico. Areas also exist 

 in the California-Utah province and in eastern New Mexico, although they 

 are as yet unstudied. The main typical area, however, is in central Texas, 

 and is so extensive that deductions as to its subdivisions have required much 

 time ; and although I have been constantly studying it for many years, not 

 until now have I felt justified in dividing it into well-defined terraues. I 

 now propose to show by stratigraphic and paleontologic proof that the 

 Comanche series is divisible into several separate and distinct terraues, the 

 lower two of which may possibly be of pre-Cretaceous age. 



Definition of the Terranes. 



CONSTITUTION OF THE COMANCHE SERIES. 



C. The Washita, or Indian Territory Division. 

 11. The Deuison Beds. 

 10. The Fort Worth Limestone. 



9. The Duck Creek Chalk. 



8. The Kiamitia Clays or Schloenbaehia Beds. 

 B. The Fredericksburg or Comanche Peak Division. 



7. The Goodlaud Limestone. 



6. The Caprina Limestone. 



5. The Comanche Peak Chalk. 



4. The Gryphcea Rock and Walnut Clays. 



3. The Paluxy Sands. 

 A. The Trinity Division. 



2. The Glen Rose or alternating beds. 



1. The Trinity or Basal Sands. 



