198 GEOLOGICAL SURVEY OF NEW JERSEY. 



of them identical with species now growing in the vicinity of 

 Bridgeton, such as Ilex opaca, Nyssa sylvatica, &c.* 



A comparison between this fossil flora and the living flora of 

 eastern North America indicates a close identity between the 

 former and that now in existence at about the latitude of Vir- 

 ginia. In many of its elements it is unique and distinct from 

 that of any other American Tertiary horizon. The collections 

 of Eocene and Miocene plants which have been made in the 

 West contain different species, and those from Bridgeton are 

 either rare or entirely wanting in them. As a whole the flora 

 is more nearly comparable with that of certain European Upper 

 Miocene localities, and we may regard it as that which immedi- 

 ately preceded the close of the Tertiary period, and this conclu- 

 sion is emphasized by the well-recognized fact that in Europe 

 biologic evolution was in advance of America, so that the 

 European Eocene flora is largely comparable with the American 

 Miocene, European Miocene with American Pliocene, and 

 European Pliocene with the American living flora. 



On the whole I am inclined to consider it as more recent in 

 age than that of any other recognized Tertiary horizon in Amer- 

 ica, but final conclusions in regard to it cannot be arrived at until 

 a number of species collected during the progress of this investi- 

 gation have been more critically examined. 



Qtiaternary Period. Towards the latter part of the Tertiary 

 period an era of elevation began, which raised the northern part 

 of the North American continent hundreds of feet above its 

 former level, and extended the shore-line far out beyond its 

 former or its present position, so that the edge of the continent 

 was about where we now find the loo-fathom contour to be, form- 

 ing a broad expanse of coastal plain, extending out to this line. 

 It was apparently the period of maximum land area for this 

 region. 



Up to this time in the world's history we have reason to believe 



* The results of preliminary studies of this flora may be found in several papers by the writer, as 

 follows : 



1. " Palseobotany of the Yellow Gravel at Bridgeton, N. J." Bull. Torrey Bot. Club, Vol. XIX 

 (1892), p. 330. 



2. "New Species of Leguminous Pods from the Yellow Gravel at Bridgeton, N. J." Ibid, Vol. 

 XXIII (1896), p. 46. 



3. " A New Fossil Monocotyledon from the Yellow Gravel at Bridgeton, N. J." Ibid, Vol. XXIV 

 (1897), p. 329. 



In the above-quoted papers may also be found references to the work of others on the same subject. 



