WICHITA FORMATION OF NORTHERN TEXAS 125 



the lower beds only in his correlation. It may be that further 

 studies will show that the overlying beds of the Winfield limestones 

 of Kansas are represented here. 



DISCUSSION BY GEORGE H. GIRTY 



The equivalence in a general way of the fossiliferous late 

 Carboniferous beds of Kansas and Texas has long been recognized 

 and in both cases they have very generally been cited as Permian. 

 Cummins, 1 partly on stratigraphic and partly on paleontologic 

 evidence, reached the conclusion that the Fort Riley limestone 

 of Kansas occupies a position at the top of the Wichita formation 

 of Texas. The Fort Riley is the middle formation of the Chase 

 group, the lowest group of the Kansas Permian, so that the bottom 

 of the Wichita may well be as low as the base of the Permian of 

 Kansas. This correlation of Cummins is probably the most pre- 

 cise and the best sustained of any, and it is also in accord with some 

 recent paleobotanic evidence. Mr. White states in the present 

 paper in discussing the fossil plants which he obtained from the 

 Wichita formation that the latter is probably referable to the Chase 

 group of Kansas. 



Not until recently, it seems to me, has adequate evidence been 

 adduced either for distinguishing the Permian of Kansas and that 

 of Texas sharply from the underlying Pennsylvanian or for cor- 

 relating them with the Permian of Europe. C. A. White found 

 the Wichita fauna to have essentially a Pennsylvanian ("Coal 

 Measures") fades, in which, however, certain characteristic 

 Permian Ammonites occur. A similar conclusion seems to be 

 demanded by the evidence of the present collections. 



In all, 75 species have been discriminated in the Wichita collec- 

 tions which I have studied, the local distribution of which is shown 

 in the table prepared by Mr. Gordon accompanying the present 

 paper. The identifications naturally vary in precision and refine- 

 ment. In many cases it has been possible to name only the genus 

 to which a species belongs. This is sometimes due to the fact 

 that the species is undescribed. In a few instances species have 

 been cited by comparison with others, e.g., Bellerophon off. harrodi. 

 1 Trans. Texas Acad. Sci., II (1897), 98. 



