CORRELATIONS 673 



lowest member, the Brush Creek bed, with the middle of the Pottawatomie 

 formation. 



The first correlation, that of the Ames limestone with the Oread lime- 

 stone, or possibly the base of the Shawnee formation, is in complete 

 agreement with the writer's conclusion, based on the fauna as represented 

 in West Virginia. 



However, the writer made no attempt to correlate the lower Conemaugh 

 with the Kansas section. Miss Mark places the lowest fossiliferous beds 

 of the Conemaugh, the Brush Creek, approximately on a level with the 

 middle of the Pottawatomie formation. That would probably be some- 

 where in the upper part of the Kansas City formation. However, the 

 Brush Creek does not constitute the base of the Conemaugh, but is from 

 80 feet to a much greater height above it. Neither is the middle of the 

 Pottawatomie the base of the Kansas beds supposed to rest on the top of 

 the Allegheny, or Des Moines, of Kansas. This interval is larger in 

 Kansas than it is in Ohio and West Virginia, but is insufficiently so to 

 seriously influence the results attained in this paper; that is, for our 

 present purposes, that difference is negligible. 



The size and character of the Conemaugh fauna is such as to make its 

 place in the Kansas succession fairly certain. It is quite certain that it 

 does not belong much higher in the Kansas section than the place assigned 

 to it, since the most of the fauna is characteristic of Series II, and pos- 

 sibly some of it the basal part of Series III, but none of it is characteristic 

 of Series IV, the beds referred to the basal Permian. 



Consequently the remainder of Series III is left for the non-marine 

 Conemaugh and the Monongahela formations — that is, the upper part, 

 or most of the Shawnee and the Wabaunsee stages, as limited elsewhere 

 in this paper. 



Leaving the Pennsylvanian part of the section, with its long-lived spe- 

 cies and sluggish development of forms, and turning to the higher beds, 

 we face a different set of conditions. 



Thus, the Fusulinre at the base of Series IV branched in two directions. 

 One of these developed the true Schwagerinas in Kansas and Texas, and 

 another into long, slender, complicated Fusulinas, found in other regions, 

 quite different from the regular, tiny, fusiform species which characterize 

 the Pennsylvanian, though a few of the latter persist into the basal Per- 

 mian. Higher up, elsewhere in the Permian, these elongate forms attain 

 gigantic proportions for Paleozoic Foraminifera, as one specimen, pre- 

 serving hardly half its length, must have been over 50 millimeters long 

 and 5 millimeters in central diameter. 



