398 PICTURESQUE SKETCHES 



present state of the earth's surface. Marvellous, too, 

 as the results of investigation have been with regard 

 to this fauna, it ought not to be forgotten, that it 

 offers in many important respects an approximation 

 to existing conditions, pointing rather to the increase 

 of land in small spots, such as islands, than to any 

 other change. The largest reptiles now existing fre- 

 quently live in muddy spots, without any luxuriant 

 vegetation in their vicinity, and far removed from 

 the haunts of quadrupeds and birds. They are well 

 known to bury themselves in mud, which often 

 hardens about them, and they remain in this way 

 in a state of torpor, until returning moisture their 

 muddy district being again flooded recals them to 

 life and activity. The marine reptiles, and the huge 

 land reptiles of the oolites, may thus have been very 

 near neighbours, and the low muddy banks, scarcely 

 lifted above the level of high water, and tenanted by 

 the Plesiosaurus, may well have been succeeded or 

 accompanied by low land of the same kind, on which 

 the Megalosaurus could find food and shelter. 



But there is considerable difference in the geogra- 

 phical position of those districts near which land ex- 

 isted during the carboniferous and the oolitic period. 

 In the former we see coal or accumulations of ve- 

 getable matter dispersed in many isolated spots in 

 Europe, as on the Rhine near Diisseldorf, in Belgium, 

 on the Moselle near Nancy, almost throughout France 

 (although in quantities so small that the beds are 

 rarely worked), in the north of Spain, in Kussia at 

 the mouth of the Don, in Silesia, and in Bohemia. 

 On the other hand, it is only in western England, 

 western France, and central Germany that the rep- 



