68 GEOLOGICAL MEMOIRS. 



strated to have taken place in some countries) was not the result of a 

 greater altitude of those countries during the diluvial period ; neither 

 was their melting due to a local sinking, but the result of some general 

 phsenomenon, which has restored to these latitudes a higher tempera- 

 ture, and has banished glaciers and the animals which live in their 

 neighbourhood to the extreme north, or to the summits of the highest 

 mountains. Nevertheless, supposing the ancient glaciers to have 

 prevailed to a greater extent, it is astonishing that no geological trace 

 of them can be found in Auvergne, a country presenting much more 

 elevated summits than others which bear traces of what are considered 

 to be undeniable evidence of glacial action. M. Rozet has justly 

 observed, that the scoriae are all reposing in their places on the craters ; 

 the rough edges of the lavas, basalts and trachytes are as strongly 

 marked as they could have been from their first formation ; and the 

 numerous heaps of detrital matter have none of the characters of 

 moraines, but are such as would be produced by sudden, \dolent, and 

 successive inundations. 



Possibly volcanic action, whichhas beensointense on these mountains, 

 has prevented the formation of glaciers by melting the accumulated 

 snow : this would account for the many inundations this region has 

 experienced, a phsenomenon which is seen frequently to occur on the 

 lofty mountains of both North and South America, where it occasions 

 prodigious ravages. 



From what has been said, it is evident that the climate of Europe, 

 if not of the whole northern hemisphere, was very different during 

 the alluvial period from that of the Pliocene, and also from that 

 of the present time. It is impossible therefore to admit the opinion 

 of M. Pictet, who considers the diluvian fauna as a transition to the 

 creation of Man ; for the admirable mechanism of the present order 

 of things would be deranged in every part by a recurrence of the 

 diluvial phaenomena. The question of the introduction of Man into 

 Europe before the end of the alluvial period might here be discussed ; 

 but the traces of his existence are so uncertain, and the bones described 

 as human have so soon been shown to be erroneously named, that it 

 is impossible to be too circumspect and cautious on a question so im- 

 portant. 



We shall conclude this account of the characters of the animals 

 that existed during the volcanic period of Auvergne by the following 

 summary. 



P. In Auvergne three distinct faunas exist, which mark the 

 Miocene, Pliocene, and Diluvian periods : the first is preserved in the 

 lacustrine beds of Limagne ; theT second in the older pumiceous con- 

 glomerates; the third in the more recent conglomerates, under the 

 newest of the basalts, in a great number of taluses at the foot or on 

 the sides of the hills ; and lastly under the lavas, in their fissures, 

 and in the travertine and mud of some caverns. 



2°. The Alluvial period commenced before the latest basaltic erup- 

 tions, and continued till after the formation of the volcanic craters 

 and their lava-floods. 



3°. This last period has been styled Diluvial, but improperly ; since 

 that name suggests an abrupt and instantaneous phsenomenon, and not 



