86 THE PERMO-CARBONIFEROUS RED BEDS OF 



present basal members of the Concmaugh series, must be conceded, since no red 

 beds whatever are found from the base of the Pottsville up to the top of the Alle- 

 gheny, and none worth considering until after the epoch of the Upper Mahoning 

 sandstone. 



' ' The sudden appearance or disappearance of red sediments after their absence 

 from a great thickness of strata is always accompanied by a great change in life 

 forms, and the present one is no exception. In fact, the invasion of red sediments 

 succeeding the Mahoning sandstone epoch of the Concmaugh may well be con- 

 sidered as the 'beginning of the end' of the true Coal Measures, both from a litho- 

 logical as well as a biological standpoint, and hence it is possible that the best 

 classification, aside from the convenience of the geologist, would leave the Mahoning 

 sandstone in the Coal Measures, and place the rest of the Concmaugh, as well as the 

 Monongahela series above, in the Permo-Carboniferous. This reference is also 

 confirmed by the character of the fauna and flora, both of which contain many forms 

 that characterize the Permo-Carboniferous beds of Kansas and the West, as may 

 be seen in the lists published on a subsequent page under the detailed description 

 of the principal Concmaugh strata." 



PRINCE EDWARD ISLAND AND NOVA SCOTIA. 



The age of the red rocks in Prince Edward Island, adjoining portions of 

 Nova Scotia and New Brunswick, was, by error in the interpretation of the 

 fossil reptile Bathygnatlms, by Cope, fixed as Triassic. They are now defi- 

 nitely known to be Permian or Permo-Carboniferous. Russell "^ has summa- 

 rized the evidence for the Triassic age of the beds in Prince Edward Island^ 

 and has shown that there is no reason to believe Triassic to be present: 



"Conclusions. — The absence of Newark fossils in the rocks of Prince Edward 

 Island; the close lithological similarity of the beds in the upper and lower portions 

 of the sections there exposed, the lower rocks being Permo-Carboniferous; and the 

 lithological difference of the rocks from the sandstone and shales of the Newark 

 system, seem to be sufificient ground for not considering any portion of the stratified 

 rocks of Prince Edward Island as belonging to the Newark system." 



Huene'' and Case'' have shown that Bathygnathus boreal is is a Permo- 

 Carboniferous reptile closely related to Dimetrodon. 



Matthews'* has given the following account of the deposits in Prince 

 Edward Island, which shows clearly the similarity in the conditions of deposi- 

 tion to those which prevailed during the formation of the Red Beds in western 

 North America : 



"GEOLOGICAL CYCLES IN MARITIME PROVINCES. 

 "Carboniferous Cycle. 



"* * * The millstone grit is essentially a part of the Coal Measures, but by 

 the greater prevalence of red sandstones and shales shows a relation in its climate 

 and conditions to the underlying Lower Carboniferous series. 



» Russell, U. S. Geol. Survey Bull. No. 85. Correlation Papers— The Newark System, chap, in, p. 25. 



'' Huene, Neues Jahrb. fur G. M. u. P., Beilage Bd., 1905, pp. 321-353. 



" Case, Science, n. s., vol. xxii, 1905, p. 52. 



<■ Matthews, Roy. Soc. Canada, Proc. and Trans., vol. 11, sec. iv, p. 121, 190S. 



