from the Comanche to the Dakota Cretaceous. 175 



rapid sedimentation, the lithology changes rapidly. Shale beds 

 change to sandstone sometimes in a few rods. Evenly strati- 

 fied sandstone suddenly becomes distinctly cross-bedded. Masses 

 of nodular concretions, or soft, spongy, clay masses appear and 

 disappear with no apparent regularity. 



The only distinguishing characteristic of the entire series is 

 the great number of clay-ironstone concretions which are found 

 from the lower Spring Creek to the upper Reeder. These con- 

 cretions are of all sizes and shapes ; round, oblong or angular, 

 often nearly cubical. On exposure to the air they usually 

 break with a conchoidal fracture, exposing cutting edges, and 

 form fragments sometimes box- or cup-shaped covering the 

 slopes and often rendering them conspicuously brown for miles. 



Dr. Lester F. Ward first found the fossil leaves on Chatman 

 Creek. An hour's search among the broken fragments of rock 

 lying on the surface revealed over 100 specimens. Dr. Ward 

 identified the leaves and under the date December 6th, 1897, 

 kindly wrote me, in part, as follows : 



" The most common species is Proteoides daphnogenoides 

 Heer, an original Dakota group species, described by Heer in 

 the earliest paper on the plants of that formation, his Phyllites 

 cretacees du Nebraska, 1866, and since found to be a very com- 

 mon species, but our forms are rather smaller than the average. 



" We also seem to have Embothrites daphneoides Lx. ; then 

 there are a number of leaves that I refer to Eucalyptus. I think 

 E. Geinitzi, Heer, is among them, and there is certainly one new 

 species.* It is just possible that we also have Laurus Plutonia, 

 Heer." 



It may be of interest to observe that the Chatman creek 

 locality where these leaves were found is not more than a mile 

 from the place on upper West Bear creek from which Cragin 

 reports "meager fragments of dicotyledonous leaves." 



The " discovery of the true base of the Dakota group "f can- 

 not but be of interest to geologists. It is to be hoped that the 

 subject may soon be worked out in greater detail. 



The writer would here make grateful acknowledgment to 

 Dr. Lester F. Ward not only for assistance and encouragement 

 in the field, but also for interest taken in the identification of 

 fossils and correction of this manuscript, and to Mr. Jesse 

 Greenleaf of Greensburg, Kansas, who kindly conducted Dr. 

 Ward and myself to the typical localities. 



Southwest Kansas College, 



Winfield, Kansas, December 27th, 1897. 



* Since writing this article Dr. Ward has named this species Eucalyptus GouldiL 

 See Bulletin of the Torrey Botanical Club, vol. xxiv, December, 1897, pp. 576-577. 

 f Lester F. Ward, Science, N. S., vol. vi, Nov. 26, 1897, p. 815. 



