NORTH AMERICA AND THEIR VERTEBRATE FAUNA. 87 



"Permian Subcycle. 



"The rocks of this period * * * are largely spread in Prince Edward Island. 

 Much of the phenomena of this time are beyond our observation, as the sediments 

 of the period are, to a great extent, concealed beneath the waters of the Gulf of St. 

 Lawrence. 



"The terrane begins with a conglomerate well shown near Pictou, in Nova 

 Scotia, and extending thence along the northern shores of Nova Scotia into New 

 Brunswick. Mr. Fletcher's account'' of the strata of this terrane recalls in many 

 respects the conditions and aspect of the Upper Devonian rocks of this region. The 

 great preponderance of red shales and red sandstones, the prevalence of plant re- 

 mains in many beds, the occasional presence of nodular or 'botryoid' limestones, 

 all suggest deposits which may have been laid down in a comparatively dry climate. 

 * * * They suggest that the Carboniferous plain * * * was now reduced in area 

 to a tract including the present southern shallows of the Gulf of St. Lawrence * * * 

 on this extended plain, with rivers entering it from the west and south, would have 

 been spread out the red sands and muds which now form the bulk of the Permian 

 deposits of Acadia." 



In his description of the Triassic cycle, in the region around the Bay of 

 Ftindy, Matthews, after describing the prevalence of volcanic activity, 

 divides the sediments into three groups: 



The lowest is composed of "bright red sandstones with a cement more 

 or less calcareous, well laminated, and often showing oblique lamination." 

 ' * * * A drier and probably colder climate" prevailed at this time. 



The second group shows a "sudden transition to coarse pebbles," such 

 as those of a shingle beach, "often without a matrix," except by secondary 

 infiltration. 



The third group is made up of sandstones and shales, mostly reddish- 

 brown, with some gray sandstones. 



This last cycle may be Jura-Triassic. There are no data yet for deter- 

 mining the exact time limit. 



» Fletcher, Can. Geol. Surv., vol. 5, n. s., part 2, rep. p., p. 108. 



