Reviews — R. Etheridge's Manual of Geology. 567 



"well acquainted with their palEeontology, and also as affording an 

 example of his mode of treatment of the several systems which 

 succeed. The remaining notices must be brief. 



Three chapters are devoted to the " Middle Palgeozoic Strata," 

 comprising the Devonian and Old Eed Sandstone. The author gives 

 us the views of Prof. Geikie on the several lakes or basins in which 

 the Old Eed Sandstone of Britain was deposited : also a very detailed 

 description of the Devonian rocks, their correlation and fauna. 

 "Perhaps during no period in the physical history of the British 

 Islands has such an assemblage of Actinozoa occurred as that which 

 specifically characterizes the Middle Devonian rocks of South and 

 North Devon, as well as the Ehenish provinces, Scandinavia, and 

 North America " (p. 200), " With the exception of the fishes of the 

 Old Eed Sandstone (120 species), the Brachiopoda is the largest 

 group of the British Devonian rocks. We should expect this when 

 we know that no less than 61 genera and over 1100 foreign described 

 species have passed through the hands of European, American, and 

 British palaeontologists. Of these 1100 species only 114 are British " 

 (p. 202). We have reason to rejoice in the reflection that our native 

 palgeontologists have been comparatively merciful. 



Six chapters are devoted to the " Upper Paleeozoic Strata," or in 

 other words to the Carboniferous system, which in England, according 

 to the author, when fully expanded, admits of division into the 

 following six groups, not, however, to be found together in every 

 district. 



Coal Measures ) tt n 



Millstone Grit } ^PP^^ ^^'^^P- 



Toredale Eocks \ 



Scar Limestone ( y p, 



Lower Limestone Shales I "" 



Calciferous Sandstone ) 



Subsequently this is replaced by a quaternary grouping. 



The author devotes a chapter to general considerations of the 

 Carboniferous system, and we find at p. 225 the remarkable state- 

 ment that the Upper or true Coal Measures were chiefly, if not 

 entirely, " terrestrial or land formations." Surely these extensive 

 accumulations, in places 12,000 feet thick, were laid down in water, 

 though such water may have been fresh or brackish for the most part ; 

 even if the Coal itself, which forms but a fraction of the Coal-measures, 

 happened to have been formed on a land surface. In connection 

 with the Coal areas of England, he makes the following state- 

 ment (p. 22B), "These Coal-fields are separated at the surface by 



the overlying New Eed Sandstone They are, however, 



connected underneath." Surely this is not so in all cases, since the 

 three great Coal areas of Durham, Lancashire, and South Yorkshire 

 are separated at the surface by loioer beds, and cannot therefore 

 possibly be connected underneath, although they may have once 

 formed parts of a continuous basin of deposit. 



Chapters on the Carboniferous strata of Scotland and Ireland, on 

 the Coal-fields of the Continents of Europe and America, and General 

 Considerations relative to the history of Coal serve to show how 



