THE ANCIENT MAMMALS OF BRITAIN, 307 



a, single gioup. The Roe Deer {Capreolus caprea), which is 

 more a southern than a northern form, is found in many of the 

 caverns, but is rare in the brick-earths ; while the Reindeer 

 {Rivigifer tiwandus)^ although common in the caverns and 

 superficial deposits both of England and Scotland, is, as 

 already mentioned, quite unknown to the east of London. 

 The Wild Boar, which is one of the most recently exterminated 

 British Mammals, requires a mere mention ; but the Hippo- 

 potamus of the British Pleistocene deposits, which is speci- 

 fically inseparable from the common African species, is one of 

 the most important of the whole Fauna, so far as climatic 

 conditions are concerned. Occurring commonly in the river- 

 gravels and brick-earths of the south and midland districts of 

 England, its remains are less frequent in caverns, although 

 found as far north as Yorkshire. In our opinion, more import- 

 ance is attached to the occurrence of the remains of this animal 

 in a deposit than those of any other Mammal, since we cannot 

 conceive it possible that the creature could have existed except 

 where the rivers were more or less open throughout the year. 



Elephants were represented by the Mammoth {E/ephas 

 prhnigenius), which may be considered merely as a northern 

 hairy representative of the existing Indian species, and the 

 so-called Straight-tusked Elephant {E. aiifiquus)^ which 

 approximated in the structure of its teeth more or less 

 markedly to the African Elephant. Bounded to the south- 

 west by the Pyrenees, and found but sparingly to the south 

 of the Alps, the Mammoth ranged northwards to Siberia, 

 where, as already said, its frozen carcases are from time to 

 time discovered, and where it must have existed in vast herds. 

 It has recently been attempted to show that the Mammoth 

 lived and died befo:e the Glacial Epoch; but although its 

 remains undoubtedly occur on the old land surfaces upon 

 which the post-glacial deposits were laid down, the opinion of 



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