358 Bake*(xelVs Litroductioti to Geolocru, 



to- 



known coal districts, which well deserve the attention of landed 

 proprietors. The parts that relate to the original formation 

 of coal in fresh-water lakes or marshes, will claim the atten- 

 tion of the speculative geologist. Chapters 1 1. to 13. describe 

 the Upper Secondary Strata, from the magnesian limestone to 

 chalk. The different formations comprised in this class were, 

 till very recently, little studied either in this country or on the 

 Continent. The transition rocks contain almost exclusively 

 the remains of marine animals. The coal strata, resting upon 

 the transition strata, contain almost exclusively the remains of 

 vegetables, and occasionally strata with fresh-water shells. 

 '* A great change appears to have taken place in the condition 

 of our planet after the deposition of the coal strata ; for the 

 upper secondary strata contain principally the remains of ma- 

 rine animals, and it is in these strata that the bones of verte- 

 brated animals are first distinctly observed. Among these we 

 find the bones of the mighty monsters of an ancient creation, 

 whose extraordinary forms are still more astonishing than 

 their immense magnitude. Some of these animals of the 

 saurian or lizard tribe attained the length of forty feet or 

 more, and appear, from the structure of the teeth and the or- 

 gans of motion, to have united to the voracity of the croco- 

 dile, the power of darting through the water on their prey 

 with inconceivable rapidity. Others had necks so long, that 

 when extended out of the water they must have resembled 

 immense hydras." 



Much obscurity formerly prevailed respecting the classifica- 

 tion of the secondary strata on the Continent. This Mr. Bake- 

 well has attempted to unravel. He explains the points of resem- 

 blance and dissimilarity which exist between the magnesian 

 limestone, the red marl, and lias of England, and the zetch- 

 stein, the gres bigarre, the calcaire agreyphites, and the mus- 

 chelkalk of the Continent. Mr. Bakewell states that the lower 

 part of the lias is wanting in the English strata, and that the 

 gres rouge ancien, the gres des vosges, and the gres bigarre of 

 the French, are only the lower, middle, and upper parts of the 

 red marl and sandstone, which are more fully developed in 

 France than in England. The diflference between the French 

 and English formations of red marl and lias is not greater 

 than what exists in distant parts of the same formation in 

 England. Our author has also traced the identity of the 

 English lias and oolites, with the calcarean formation of the 

 Jura and the Alps. 



A series of fresh-water strata, between the oolite and the 

 chalk, occurs in the southern counties of England ,* but these 

 are probably local formations ; they are remarkable for con- 



