Kansas Academy of Science. 213 



THE ( OMANCHEAN OF CENTRAL KANSAS.^ 



W. H. 'I'WKN IIOFKI.. 



INTRODUCTION. 



THE Comanchean of central Kansas is represented in the 

 marine Mentor beds and associated strata. That these 

 beds are of Comanchean age has been known to stratigraphers 

 for many years ; but so far as students who are not expert 

 stratigraphers are concerned, there has been some uncertainty 

 as to their exact stratigraphic position. Three things are 

 responsible for this state of affairs, namely: the general in- 

 accessibility of the literature relating to these beds ; the fact 

 that no Comanchean is shown in central Kansas on the geo- 

 logic map of the state which has been published by the State 

 Survey; and that description of the Mentor beds in volume 

 11 of the State Survey is given under the title of "The Dakota 

 Sandstone." 



It is the hope of cleaning up this uncertainty that has been 

 the incentive for the preparation of this article, which is in- 

 tended to be preliminary to a more extended treatment of 

 these strata and their faunas. 



At the close of the article there is given a list of the more 

 important papers in which the Comanchean of central Kansas 

 has been considered. The small map shows the distribution 

 of the beds. 



SUMMARY OF INVESTIGATION. 



For many years the Mentor and associated beds were in- 

 cluded in the Dakota sandstone, of which the base was hence 

 considered to be of marine origin. As a consequence of this 

 assumption there are numerous references in geological litera- 

 ture to the marine fossils in the Dakota sandstone of Kansas, 

 and some hypotheses have been erected on their supposed pres- 

 ence. 



The first person who appears to have noticed the fossils at 

 the base of the red Cretaceous sandstones of central Kansas 

 was Dr. John L. LeConte. While with a party making sur- 

 veys for the extension of the Union Pacific railroad to the west 

 of Salina, he collected fossils to the south of Spring creek cross- 



1. Published by permission of the director of the Kansas GeoloRical Survey. 



