WARD.I HI8T0KICAL KEVIKW OF OPINION. 411 



coal and plaut bearing beds lying along the Smoky Hill Fork of tLe 

 Kansas River. In his report of a survey of this region' he gives it as 

 his opinion that the lignitic strata of this region are older than those 

 of the Upper Missouri, which he admits to be Miocene (p. Go). He 

 states that specimens of luoceramus were found with the coal in Raton 

 Pass, indicating its Cretaceous age, and then proceeds to adduce rea- 

 sons for discrediting the evidence furnished by vegetable remains. 



The followiug year (1869) Prof. E. D. Cope, in an exhaustive paper 

 on the vertebrate paleontology of America, published in the Transac- 

 tions of the American Philosophical Society (Vol. XIV), in comment- 

 ing ujion Jschifrosanrus antiqxK-s, Leidy, from Moreau River, Great Lig- 

 nitic of Nebraska, speaks of that formation as "perhaps of the Cre- 

 taceous age" (p. 40), and with more confidence later on assigns Hadro- 

 saurus ? occidentalism Leidy, to the "?Cretaceous beds of Nebraska," 

 although Pal(voscincus costntus, Leidy, is still kept in the " upper Juras- 

 sic Bad Lauds of Judith River." In the tabular exhibit at the close of 

 this nxemoir the first of these species is placed in the Cretaceous col- 

 umn ; the second is also placed in that column, but with au accompany- 

 ing mark of interrogation, while the third is assigned to the Jurassic 

 column. 



The Third Volume of the United States Geological Exploration of 

 the 40th Parallel, relating to Mining Industry, bears date 1870, and con- 

 tains an important chapter (VII) from the pen of Mr. King on the Green 

 River Coal Basin, in which he maintains that the extensive coal-bear- 

 ing deposits of this region are chiefly of Cretaceous age, but admits 

 that the uppermost strata pass into the Tertiary and become fresh- 

 water beds. He also declares that the true fresh-water Tertiary strata 

 of the Green River group overlie the coal beds unconformably at all 

 points. "The fossil life," says Mr. King, "which clearly indicates a 

 Cretaceous age for the deepest members up to and including the first 

 two or three important coal beds, from that point gradually changes 

 with a corresponding alteration of the sediments, indicating a transition 

 to a fresh- water period. The coal continued to be deposited some time 

 after the marine fauna had been succeeded by fresh-water types. The 

 species of fossils are in no case identical with the California Cretaceous 

 beds, which occupy a similar geological position on the west of the 

 Sierra Xevada. Their afBnities decidedly approach those of the Atlantic 

 ■slopes, while the fresh-water species, which are found in connection with 

 the uppermost coal beds, seem to belong to the early Tertiary period." 

 And, speaking of the unconformity of strata above referred to, he re 

 marks : " Whatever may be the relations of these beds in other places, 

 it is absolutely certain that within the region lying between the Green 

 River and the Wahsatch, and bounded on the south by the Uintah 



' Notes on the Geology of the Survey for the extension of the Union Pacific Rail- 

 way, E. D.,from the Snioky Hill River, Kausas, to the Bio Grande. By John L. 

 LeContH, M. D. Philnil.-lphia. Frbrnary, 1S63. 



