FLORA OF THE LANCE FORMATION AT ITS TYPE LOCALITY, 

 NIOBRARA COUNTY, WYOMING 



INTRODUCTION 



The flora of the Lance formation has been the subject of considerable discussion 

 in the past because of its connection with the controversial Mesozoic-Cenozoic 

 boundarj^ problems. Several years ago it became apparent that many of the fossil 

 plants supposed to have been collected from the Lance formation of Wyoming, 

 Montana, and the Dakotas were in reahty obtained from beds which are above and 

 younger than the Lance formation as originally defined.^ It has seemed wise, there- 

 fore, to Hmit the scope of this report to the description and discussion of plants 

 known definitely to have come from the Lance formation at its type locahty. 



Although plants were collected by Knowlton from the type Lance (then called 

 the " Ceratops beds of Converse County ") as early as 1896,- they were only partially 

 identified and have never been described or figured. These plants are now in the 



FiG. 1 — Index map showing location of Lance Creek area 



' Dorf, E., Carnegie Inst. Wash. Pub. No. 508, pt. I, 33, 35, 1938. 



2 Stanton, T. W., and Knowlton, F. H., BuU. Geol. Soc. Amer., vol. 8, 128, 1897. 



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