114 PROF. J. LOGAN LOBLEY, F.G.S., F.E.G.S., ON THE HISTORY 



toads except the natterjack, all frocjs except one species, tlio 

 nightingale, the Kouian snail {Hciic poraatia) and Cyclostoma 

 ehgans. 



Furthermore, it appears that the area of the settlement of the 

 Xorth-Eastern Immigrants was bounded south-westwards by the 

 Kiver Garonne, which does not seem to have been crossed by 

 them, while the far northern lands of Scandinavia and Russia 

 were also unyisited by these Asiatic animals, so that their area 

 of occupation is well clehned. 



To this immigration Europe is indebted for no less than 

 twenty-eight mammals, of which nine are still, or were recently, 

 living in the British Islands. These are the beaver, the harvest 

 mouse, the pole cat, the common shrew, the stoat, the vole, the 

 water vole, and another species, Arvirola glarcalus, and the 

 weasel. The remainin^^ eighteen are either now living in parts 

 of the European continent, or, as their bones attest, did so in 

 Quaternary times. These are the Arctic fox, the glutton, the 

 tailless hare, three species of hamster, the jerboa, two species of 

 lemmings and three species Arvicola, the liobak marmot, and 

 two species of pouched marmots, the moose deer and another 

 species of Alecs, the musk ox, the Saiga antelope and the 

 Siberian reindeer. 



To this immigration we also owe our thrushes, bullfinches 

 and the nuthatch, and from it we have received the sand lizard 

 and two other species of lizards, the viper and the frog, Rana 

 arvalis. Of insects, the tiger beetle and several other beetles, 

 and some European butterflies, may l)e ascribed to the North- 

 Eastern Immigration. 



As pointing to, if not proving, the former sea connection 

 between the Arctic Ocean and the Aralo-Caspian region, it may 

 be mentioned here that the Phoca caspia of the Caspian Sea is 

 very like the seal of the Sea of Aral and the Phoca baltica of 

 the Gulf of Finland, as well as the seals of the Arctic seas. 

 There are also in the Caspian two s})ecies of My sis, closely 

 related to the Mysis ocidctta of the Arctic seas, as well as some 

 other crustaceans of an Arctic character. 



Some of the migrants from Siberia seem to have advanced 

 westwards into Europe for a certain distance and then to have 

 retreated towards their original homes. Such, for example, 

 is the Saiga antelope, or Saiga tartarica, wliich is now only lound 

 in the East of liussia near to the Asiatic border. 



The very interesting Cromer Forest Bed, abounding as it 

 does with mammalian remains, has been the subject of con- 

 siderable discussion as to its geological age. It is usually 



