172 



every recent class, but the species indicate a great diffe- 

 rence in climatal conditions from that now prevailing in 

 this part of the world ; we recognize them as allied to 

 present tropical or sub-tropical forms. All the existing 

 orders of Mammalia have been observed. The Quadru- 

 mana, Cheiroptera, Insectivora, Marsupialia, Cetacea, and 

 Pachydermata, are found in the Eocene. Bhds, and 

 all the recent orders of Reptiles and Fishes, are also 

 present. 



The Eocene is remarkable fi'om the absence of Rumi- 

 nants and Carnivora ; the first indication of the former 

 occurs in Pleistocene or newer Cainozoic, The mammals 

 of the Eocene are now all extinct. Most of the Pleiocene 

 and Pleistocene are also extinct : many of these were lost 

 during the time of the northern drift, when probably the 

 last change in the configm-ation of the land took place. 

 The evidence of the organic remains indicate a great but 

 very gradual change in the climate of Europe, no doubt 

 caused by the elevation of the Alps and other mountain 

 chains, and a very considerable addition to the dry land of 

 Northern Asia. 



Before deducing any conclusions from geological facts 

 observed in the strata of the British Islands, it must be 

 obvious that the investigation of other countries is of par- 

 amount importance ; for if the Biitish sti'ata present all the 

 main facts that can be derived, from a general examina- 

 tion of the strata that have yet been examined by 

 geologists in many distant parts of the world, then we 

 can place more reliance upon any conclusions we may 

 arrive at, though based upon the negative evidence 

 afforded in this country. In India, Australia, and in 

 America, there is a constant analogy and connection 

 between the rocks of those countries and our geological 

 systems. At the last meetmg of the British Association, 

 there were maps representing large tracts of India and 



