INTRODUCTION. 21 



admitted that the vegetable remains had been derived from trees or slu*ubs 

 growing in the vicinity of marshy or muddy bottoms, and that they have 

 been buried and fossihzed at or near the place of their growth. This con- 

 clusion is liased not only upon the remarkably good state of preservation 

 of the fossil leaves, which are generally found horizontally flattened in the 

 same plane or parallel to that of the deposition of the earthy matter, neither 

 crumpled, rolled, nor lacerated, and with their borders, often even their 

 petioles attached to them, but also upon the distribution of the leaves which 

 at different localities generally represent diffei'ent species. Sometimes all 

 the leaves of a local area belong to the one species, while at a short distance 

 another group of leaves represent other species, genera, or even families. 



These remarks have been lately fully confirmed by the discovery in 

 Ellsworth County, Kansas, of a very large number of leaves embedded in 

 concretions in the same manner as remains of Carboniferous plants have 

 been preserved in the celebrated nodules of Mazou Creek, Illinois. More 

 than three thousand specimens of this kind have been collected in that 

 county by Judge E. P. West, assistant of Prof F. H. Snow, of the Univer- 

 sity of Kansas, and later by Mr. Charles H. Sternberg. The concretionary 

 specimens were found at more than twelve different localises, in groups cov- 

 ering limited areas, the largest tract being about 100 yards, the others not 

 more than 20 yards in width, altogether distributed upon a land surface of 

 5 to 8 square miles. The specimens of each locality were separately 

 collected and were also determined separately, and each lot was found to 

 be composed of leave's of from one to three species, and few of them were 

 represented in more than two or three localities. Thus, leaves of Sterculia 

 were found at one locality, at another leaves of Grewiopsis; in two or three 

 others, mostly small leaves of Betulites were collected, and in others leaves 

 of Populus kansaseana, with Diospyros rotimdifoUa, etc. As can be seen 

 upon the plates, the leaves forming the nucleus of the pebbles are in a per- 

 fect state of preservation, a number of them with their pedicels, with even 

 a small stipule at their base. Of course the fossilization of numerous leaves 

 of the same species in nodules, the distribution of different species in groups 

 at various more or less distant localities, give positive evidence of their 

 growth at the place, or at least quite near, where their remains have been 

 fossilized. 



As yet the relative altitudes of the localities where the various groups 

 of specimens have been found have not been fixed, and we do not know 

 whether the diversity of the characters of the plants might be accounted 



