33 L 



aummulitic formation occupies a middle jjlace in the Eocene 

 series, we are struck with the comparatively modern date to 

 which some of the greatest revohitions in the physical geographj 

 of Europe, Asia, and northern Africa must be referred. All 

 the mountain chains, such as the Alps, Pyrenees, Carpathians, 

 and Himalayas, into the composition of whose central and lof- 

 tiest parts the nummulitic strata enter bodily, could have had no 

 existence till after the middle Eocene period." — Manual^ p. 232. 



A still more marked case follows on the next page. 

 Because a certain bed at Claiborne in Alabama, which con- 

 tains '■''four hundred species of marine shells," includes 

 ^mong them the Cardita platiicosta^ "and some others 

 .dentical with European species, or very nearly allied to 

 them," Sir C. Lyell says it is " highly probable the Clai- 

 borne beds agree in age with the central or Bracldesham 

 group of England." When we find contemporaneity sup- 

 posed on the strength of a community no greater than that 

 which sometimes exists between strata of widely-difierent 

 ages in the same country, it seems very much as though 

 the above-quoted caution had been forgotten. It appears 

 to be assumed for the occasion, that species which had a 

 wide range in sj^ace had a narrow range m time ; which is 

 the reverse of the fact. The tendency to systematize over- 

 rides the evidence, and thrusts Nature into a formula too 

 rigid to fit her endless variety. 



" But," it may be urged, " surely, when in difierent 

 places the order of superposition, the mineral characters, 

 and the fossils, agree, it may be safely concluded that the 

 formations thus corresponding are equivalents in time. If, 

 for example, the United States display the same succes- 

 sion of Silurian, Devonian, and Carboniferous systems, lith- 

 ologically similar, and characterized by like fossils, it is a 

 fair inference that these groups of strata were severally 

 deposited in America at the same periods that they were 

 deposited here.'' 



