CORRELATION OF WYOMING FORMATION. 59 



Professor Scudder states is "an exceptionally large ratio in beds where 

 both occur." 



In contradiction of the conclusions thus drawn by Professor Scudder 

 from the fauna are those derived by Professor Lesquereux from the fossil 

 plants collected from the same beds. 



The plants collected, although fragmentary, permitted the recognition 

 of several genera and species characteristic of the Permian, with even 

 a tendency at times to a Carboniferous facies when compared with the 

 European and Virginia forms of the Carboniferous ami Per -Carbon- 

 iferous groups, respectively. Professor Lesquereux furthermore c pares 



the Fairplay flora with Fontaine's flora "f the Trias (Bhsetic) of Virginia, 

 ami finds no resemblance whatever between the forms of the two localities. 

 The same occurs on a comparison with European Trias forms also, and 

 this entire absence of even a trace of Triassic flora Lesquereux regards 

 as a strong argument for the Permian age of the beds considered. 



Scmlder, nu discussing Lesquereux's evidence, meets the possible 

 observation that this discovery of cockroaches may indicate tor America 

 an earlier advance within Paleozoic times toward later types, by remark- 

 ing that such a deduction would lie in direct opposition to what we know 

 of subsequenl periods in America. He cites one case ill favor of this 

 hypothesis, and one. which he considers stronger, against it, ami states 

 that from all evidence such an advance should rather he looked for in 

 Europe than in America. Other instances of similar discrepancies are 



found between the Paleozoic and Secondary strata at Kaigahinsk, in 

 eastern Russia, 1 and between the Carboniferous and Permian at Pilsen, 

 in Bohemia. 2 



In comparing the evidence of plants and animals, that of the latter 

 would seem to merit the greater weight, because the conditions of distribu- 

 tion and preservation of plant remains are in favor of their continuance, 

 conditions which an- not shared by animals, and, as Mr. Twelvetrees further 



suggests, it may lie that the survival of the older and more persistent forms 

 should count for less than the appearance of the new ones. 3 



1 W. It. Twelvetrees, in Quart. Jour. Geo], Soc. London, Vol. XXXVIII, p. 495. 



-Geikie, Text-book of Geology, pp. 748, 754. 



3 See a I so Geikio'p remarks, Text-book of Geology, pp. 759, 763. 



