420 FLORA OF THK LARAMIK GROUP. 



The Aiiiiual Report of the Geological Survey of the Territories under 

 Dr. Ilayck'ii for 1871, published in 1S7G, contains three very important 

 papers iii)()n this subject. The first is by Dr. Hayden hiiuselt', who 

 labors effectively to "connect the coal-bearing beds of the Laramie 

 Plains and Colorado with the vast grcmp in the Northwest," but con- 

 cedes the Cretaceous age of the Bear Kiver and Coalville deposits. He 

 says that " above the upper Fox Hills group there are about 200 feet of 

 barren beds which may be regarded as beds of passage to the Lignitic 

 group, wlii(!h more ])roperly belong with the Fox Hills group below. In 

 this group of transition beds all trace of the abundant invertebrate life 

 of the great Cretaceous series below has disappeared. * * ♦ Whatever 

 view we may tak(^ with regard to the age of the Lignitic group, we may 

 certainly claim that it forms one of the time boundaries in the geological 

 history of our western continent. It may matter little whether we call 

 it Upper Cretaceous or Lower Eocene, so far as the final result is con- 

 cerned. * * * Even the vertebrate paleontologists, who pronounce 

 with great positiveuess the Cretaceous age of the Lignitic group, do not 

 claim that a single species of vertebrate animal passes above the horizen 

 I have defined from the well marked Cretaceous group below." 



The second of these papers is by Dr. A. C. Peale, who has here per- 

 formed good service in preparing tables to illustrate the progress of 

 opinion on this subject. In addition to this, however, after stating the 

 character of his own investigations, he gives it as his opinion that "the 

 lignite-bearing beds east of the mountains in Colorado are the equiva- 

 lent of the Fort Union group of the Upper Missouri, and are Eocene Ter- 

 tiary ; also, that the lower part of the group, at least at the locality 

 two hundred miles east of the mountains, is the equivalent of a i)art of 

 the lignitic strata of Wyoming;" but he thinks that " the Judith Kiver 

 beds have their equivalent along the eastern edge of the mountains, 

 below the Lignite or Fort Union group, and also in Wyoming, and are 

 Cretaceous, although of a higher horizon than the coal-bearing strata 

 of Coalville and Bear River, Utah. They form either the upper part 

 of the Fox Hills group (No. 5) or a group to be called No. 6." 



Finally we have another exhaustive paper by Mr. Lesquereux, in 

 which he divides the arguments against the Tertiary theory into five 

 pi'opositions and answers each in detail. Important discoveries of fos- 

 sil plants had been made during the year at Point of Rocks, and these 

 are made to lend their weight to his argument. It is needless to say 

 that his conclusions remained unchanged. 



The ninth volume of the final quarto leports of the Geological Sur- 

 vey of the Territories, consisting of Mr. Meek's report on the inverte- 

 brate Cretaceous and Tertiary fossils of the Upper Missouri country, 

 appeared in 1S;G. In this report Mr. ^Meek takes the ground that the 

 Judith River beds are distinct from the Fort Union group proper and 

 of Cretaceous age, or at least probably so; but he is inclined to believe, 

 from the occurrence of similar forms iu both, that they are the equiva- 



