t;8o SCIENTIFIC RECREATIONS. 



we find the remains in more or less pure carbon forms the anthracite 

 and the graphite of the primary formations. 



Coal appears not to have been formed equally in all places during the 

 period in which it originated. The remains of plants found in these strata 

 lead us to infer, that, during that period there existed an exceedingly 

 vigorous and crowded vegetation, consisting principally of tree ferns and 

 equisetaceae, of which the Sphenopteris Hceninghaiisii (fig. 662), Pecopteris 

 aquilina (fig. 663), and Neuropteris Loshii (fig. 664), are amongst the most 



Fig. 662. 



Fig. 663. 



Fig. 664. 



beautiful that have been found, and the flora and fauna of this period were of 

 a more or less primitive kind or low order, but very luxurious. The former 

 display a decided advance, and reptiles of aquatic forms appear with large 

 and predaceous fishes. Mountain limestone, which is usually found in the 

 coal formations, includes metallic deposits, and organic remains are very 

 abundant in it. The following are specimens of the fossils 



Fig. 665. i. Bellerophon costatus. 



Spirifer glaber. 



3. Productus Martini. 



Orthoceras lateralis. 



The Carboniferous system is a very important one, as may be seen. In 

 these beds we have coal, limestone, sandstone, and shale. The Coal 

 Measures consist of grit and sandstone and shale, with coal seams. The 

 Carboniferous Limestone, or " Mountain " Limestone, has no coal in it. The 



