JURA-TRIAS IX AMERICA. 



457 



fers, Equisetse, and Ferns. Fontaine makes them B7icetic, i. e., transi- 

 tive between Triassic and Jurassic. The animals indicate the same 

 horizon. 



Fig. 723. — Dictyopyge niacrura, a Ganoid taf ter Emmons). 



The Deep Kiver and Dan Eiver coal-fields of Xorth Carolina are 

 very similar to those in Eastern Virginia, except that in the Deep Eiver 

 coal-fields the coal-bearing portion, which seems to correspond with 

 the whole of the Eichmond strata, is underlaid by 3,000 feet of barren 

 sandstone. If we call the coal-measures Upper Trias or Lower Juras, 

 these barren sandstones are certainly Triassic. In their upper portion, 

 and therefore probably' in the Upper Triassic, Emmons found jaws of 

 a Marsupial, which^he names Dromatherium sylvestre (Fig. 729). As 

 this is one of the earliest, so is it also one of the most reptilian of mam- 

 mals. According to Osborn, it had many reptilian characters of teeth, 

 e. g., conical premolars and imperfectly divided fangs, and imperfect 

 cusps in the molars (Fig. 711, a) as in the Theromorph reptiles. Until 

 the recent discoveries of Marsh, this, and perhaps another genus from 

 the same place, was the only mammal known from the Jura- Trias of 

 America. We give in Figs. 723-729 some of the plants and animals of 



Figs. 724, 725. 



Fig. 724 



-Fossils of Xorth Carolina and Richmond Coal-Basins (after Emmons): 734. 

 Walchia diffusus. 725. Podozamites Emmonsi. 



