INTRODUCTION. 



suited. It was collected in part by F. V. 

 Hayden and in part by Lesquereux or by 

 persons in correspondence with him. The 

 very earliest collection made by Hayden, at 

 Marshall in 1867, is apparently lost. The 

 types of the few species described by J. S. 

 Newberry are also preserved in the United 

 States National Museum. About 1884 ,an im- 

 portant collection was made for Newberry by 

 N. L. Britton, now of the New York Botanical 

 Garden. The larger part of this collection 

 came from mines near Erie, Colo.,, from which 

 no additional material has been procured. 

 Other parts of this collection were made at 

 Marshall and on Coal Creek. All this material 

 has been placed at my disposal by Dr. Arthur 

 Hollick. Considerable collections were made 

 by Lester F. Ward in 1883, but heretofore 

 they have only partly been described. During 

 the prosecution of the work which resulted in 

 the publication of the Denver Basin mono- 

 graph, Emmons, Cross, and Eldridge obtained 

 a number of small collections, and under the 

 instructions of Emmons larger and important 

 collections were made by Arthur Lakes and 

 G. L. Cannon. These collections, made in 

 188"9 and 1890, have not before been described. 

 A small collection from Crow Creek, near 

 Greeley, was made in 1896 by T. W. Stanton 

 and me. The largest collections obtained in 

 recent years were made by A. C. Peale and me 

 in 1908. The material in the museum of the 

 University of Colorado, at Boulder, has been 

 placed at my disposal by the custodian, Judge 

 Junius Henderson. Smaller collections or. 

 individual specimens have been communi- 

 cated by T. D. A. Cockerell, of Boulder; R. D. 

 George, State geologist of Colorado; G, L. 

 Cannon, of Denver; G. B. Richardson and 



M. I. Goldman, of the United States Geological 

 Survey; and G. I. Finlay, formerly of Colorado 

 Springs. Invaluable data regarding the sup- 

 posed upper part of the Laramie were ob- 

 tained by W. T. Lee, of the United States 

 Geological Survey, in 1915. To these men and 

 all. others who have contributed to this study 

 the appreciation of the writer is hereby ex- 

 pressed. 



Notwithstanding the fact that these very 

 considerable collections have been brought 

 together, the flora is neither large nor very 

 impressive. In the first place, although plants 

 are widely distributed in the Laramie, they 

 are rarely found in any great abundance. 

 The matrix in which they occur is usually a 

 soft, friable sandstone which is not fitted to 

 retain the plant impressions with fidelity, and, 

 moreover, it is difficult to find perfect speci- 

 mens. In attempting to present as complete a 

 picture as possible of the plant life of. the 

 time, it has frequently been necessary to 

 characterize forms on rather slender data. It 

 is hoped, however, that all are figured and de- 

 scribed adequately enough to be recognizable 

 in the future. 



A word should be said concerning the two 

 styles of plates in this report. Plates XX- 

 XXVIII were made a number of years ago, 

 when it was the custom to make pen drawings 

 of the specimens. These were drawn on an 

 enlarged scale, requiring a one-third reduction 

 to bring them to natural size. The figures on 

 Plates I-XIX were photographed natural 

 size and merely have had the outlines and 

 nervation strengthened. The impossibility of 

 having the two styles of drawings mixed on 

 the same plate accounts for the scattering of 

 the figures. 



