]S 7 o. XV. GEOLOGY. 345 



helping to explain the occurrence of a fauna in glacial 

 deposits, thought by some to indicate an interglacial episode 

 in the last British Glacial era. 



We will not enter into the question whether the area, 

 embraced by the conditions which caused the glaciation of 

 Britain, included the Arctic area, nor as to the causes, geogra- 

 phical, astronomical, or physical, that led to it ; but we think 

 it worthy of note that no records of former glacial episodes 

 have yet been discovered in the Polar lands, which were 

 tenanted by the molluscs of the Silurian, Carboniferous, 

 Liassic, and Oolitic seas, and its land covered with the rich 

 vegetation of the ' Ursa stage,' and of the Cretacean and 

 Miocene eras. 



The fauna and flora of the Arctic Palaeozoic and older 

 Secondary rocks point to a uniformity of conditions of temper- 

 ature, climate does not appear to have existed, in the ordinary 

 sense of the word, as temperature of the air affected by local 

 geographical conditions ; the striking uniformity of condition 

 appears to have been unbroken up to the close of the 

 Secondary Epoch. 



