AGE OF THE LIGNITIC DETERMINED BY ITS FLORA. 349 



Cretaceous. Of the eight species (tf .'>'(<:/;(// (h'sciil)e(l, one species is Miocene, 

 two Oligoceiie, and five I^ocenc. tSdhal andegavensis, Scii[)., and H. precur- 

 soria, Schj)., two species of the Upper Eocene of France, are very closely 

 related, the first to Sahalites communis of Golden, and the oilier to Sahalilcs 

 Grayanus, found in many localities of the Lower Lignitic from Mississip])i 

 to Vancouver. In considering the Lignitic flora by flu; specimens of fossil 

 plants from Black Buttes, Grolden, Colorado Springs, the Raton Mountains, 

 etc., where the preponch-ranee of remains of Saba/ and Flabellnria is so 

 marked, how could it have been possible, if even we had had no other char- 

 acters for direction, to refer to the Cretaceous the flora of the Lower Lignitic 

 as represented in these localities? The above speaks plainly, and shows how 

 I had to recognize the flora of Vancouver as Tertiary, from the numerous 

 specimens of Sahal sent by Prof. Evans, from Nanaimo, even if the other 

 plants of the locality had not been of Tertiary types. It was the same case 

 for the flora of the State of Mississippi, where the Palms are also in prepon- 

 derance. At Point of Rocks, four large specimens upon sandstone represent 

 the same species of Sabalites as that of Vancouver and Mississippi, S. Gray- 

 anus, which, in the ojiinion of a celebrated European paleontologist, is one 

 of the finest and most positively characterized species of the genus. 



The two species of Dryopliytlum described from Point of Rocks are 

 indicated in the table of distribution as analogous, one to the Eocene and the 

 other to Cretaceous forms. The genus Dryophyllum, as remarked already, 

 has been established for a peculiar section of the Oaks, from species as yet 

 undescribed from the Cretaceous of Belgium. The type which the species 

 represent, like some others of the same formation, does not appear to have 

 reached its full development from or at its origin. We see it, for example, 

 in the Dakota group flora in the projiorfion of two species in about one 

 hundred and thirty, while in the Paleocene flora of Gelinden, it has four 

 species in thirty, and the same number in forty-eight in the flora of Sezanne. 

 It then reappears more or less frequently in the Tertiary by analogous 

 species of Qucrcus, and may be hence followed through tin; formations, and 

 nearly without interruption to the ])resent time. From this, it is clear that 

 the reference of fossil species of this genus, when remarked in connection 

 with remains of Tertiary plants, should more aj)propriately pertain to the 

 Eocene tl)an to the Cretaceous. Therefore, if the presence of species of 

 Dryophyllum in the I'oint of Rocks flora, and that also of Pistia, Sequoia 



