1889.] XEW YORK ACADEMY OF SCIEXCES. 31 



Tertiary are other questions, but they are certainly distinct from 

 each other, — distinct in the general botanical facies of their 

 floras as well as in the absence of common species. That the 

 Fort Union flora is Tertiary, there can be no reasonable doubt; 

 it has many species in common with the recognized Tertiary in 

 the Canadian provinces of North America, in Greenland, and in 

 the British Islands, and it contains some plants which are living 

 at the present day, such as Onoclea sensihilis, Taxodmm dis- 

 tichiim, Corylus Americana, C. rostrata, etc. Moreover, the 

 grouping of the plants composing it gives it a facies which en- 

 ables one to recognize it at a glance. The abundance of species 

 and specimens of Popuhis, Viburnum, and Corylus imparts to 

 it an aspect as different from that of the flora of the Laramie as 

 are the recent floras of Europe and America from each other. 



My reasons for considering the Laramie the upper member 

 of the Cretaceous are these: — 1st. It contains an invertebrate 

 fauna that has in it many Cretaceous elements; Macira alta, 

 Cardium speciosum, and several species of Inoceramus, being 

 also found in the Fox Hill group. 2d. It contains, according to 

 Professors Marsh and Cope, a vertebrate fauna which is decidedly 

 Cretaceous in character. 3d. The somewhat numerous mammals 

 recently obtained from the Laramie by Professor Marsh are re- 

 ported by him to have decided Mesozoic characters. Among the 

 reptilian remains found in the Laramie are many Dinosaurs, a 

 group of which no representative has hitherto been seen in the 

 Tertiary, and the great horned reptiles Triceratops and Ceratops 

 are among the most remarkable of all extinct animals.' 



The Laramie group is a formation that is essentially confined 

 to the Eocky Mountain region; it forms a marginal belt on the 

 east side of the mountains, extending from Central Mexico far 

 into the British possessions. On the west side of the Eocky 

 Mountains, it stretches over to the Wasatch, but has not been 

 recognized at any point west of the summit of that range. 

 Everywhere it contains coal, frequently in large quantity and of 

 excellent quality. These coals are opened along the eastern 

 side of the Eocky Mountains at Erie, Marshall's, Florence, 

 Walsenburg, Trinidad, etc.; and from these sources the rapidly 

 growing towns of the prairie region are receiving most of their 

 fuel. On the west side of the Eocky Mountains, in Colorado, the 

 Laramie coals are more important than elsewhere; the aggregate 

 thickness in some places of several beds is fifty feet or more; 

 the coal varies in composition from hard anthracite to open- 

 burning bituminous, and much of it is of excellent purity, the 

 amount of ash ranging from two to five per cent, the sulphur 

 often less than half of one per cent. 



' See meeting of October 28th, ante. 



