MESOZOIC ERA. AGE OF REPTILES. 



345 



FIG. 398. Jaw of Dromatherium sylvestre. 



FIG 297. Section across Richmond coal-field. (After Daddow.) 



fields of North Carolina. In connection with the Coal, 

 plants have been found in considerable abundance. They 

 are those characteristics 

 of the Jura-Trias every- 

 where, viz., ferns, cy- 

 cads, and conifers. In 

 North Carolina the jaw 

 of a small marsupial has 

 been found about the middle of the series (Fig. 298). 



The coal of these Jura-Trias fields is of good quality, 

 in thick seams, and easily worked. 



4. Atlaiitosaur Beds. These we describe separately, 

 not only because they are recent discoveries, but also 

 and chiefly because they belong to an entirely different 

 horizon, viz., the uppermost Jurassic passing into the 

 Cretaceous. 



In these uppermost Jurassic beds, called Atlantosaur 

 leds, from their most abundant and characteristic genus, 



FIG. 299. P.ronto.suimis cxcolsis, x T foy. (Restored by Marsh.) 



have recently been found, in Wyoming and Colorado, 

 great numbers of most extraordinary reptiles, the largest 

 yet known, and also a bird and seventeen species of small 

 marsupial mammals. 



