Reviews — Scharff^s Origin of the European Fauna. 469 



the ancient southern fauna with the newer immigrants from the 

 north. 



" Deposits containing Arctic marine moHusca were also discovered 

 below the Boulder-clay near the shores of the White Sea, another 

 proof of the former extension of the Arctic Ocean in this dii'ection." 



Former Land-connection between Scandinavia and North Greenland. — 

 " I can only allude at present to an important feature in the physical 

 geography of Northern Europe, viz., the former continuation of the 

 Scandinavian coastline in a north-westerly direction to Spitzbergen 

 and North Greenland. The cold waters of the Arctic Ocean did 

 not communicate at all with the Atlantic at the time when the 

 above-mentioned changes occurred in Northern Eui'ope, but they 

 poured into the Baltic and the German Ocean, which was then 

 a closed bay, and brought with them the characteristic fauna of the 

 Arctic regions." 



The Lowlands of Northern Europe covered by the Sea. — "The Aralo- 

 Caspian communicated with this large northern sea, which had 

 formed on the North European lowlands, and which we may call 

 the " North European Ocean," at a time immediately preceding the 

 deposition of the Upper Boulder-clay. But the barrier which pre- 

 vented the Sibei'lan fauna from entering Europe was the strait or 

 straits which connected the two seas. We can, therefore, accurately 

 fix the period of the beginning of the migration, for it must have 

 occurred as soon as this barrier disappeared ; or, if we are able to 

 ascertain stratigraphically the first appearance of the Siberian 

 immigrants in Central Europe, the disappearance of the barrier 

 must have immediately preceded that period." (p. 462.) 



Bemains of Siberian Fauna found fossil in England. — " We know 

 that in England remains of Siberian mammals occur from the 

 Forest-bed upward, whilst none are found in older strata. It seems 

 safe to conclude, therefore, that the Sibei'ian migration took place 

 after the deposition of the Lower Continental Boulder-clay, and 

 during or just previous to the formation of the Forest-bed. But 

 the latter has been lately recognized as a Pre- Glacial formation, 

 and it certainly underlies the English Boulder-clay. How can we 

 then reconcile these two apparently very contradictory conclusions — 

 that a migration which undoubtedly set out from the East arrived 

 in Western Europe before it reached Central Europe ? 



" I have shown in a previous paper that such was certainly the 

 case with some southern Asiatic mammals, which entered Europe 

 from Greece, and migrated along the Mediterranean coast to Northern 

 Africa at a time when a land- bridge still existed between it and 

 Southern Italy, and then recrossed again to Spain, where at last 

 they turned north to appear in Western Europe, without having 

 crossed the central parts of the continent. Such, however, could 

 not possibly have been the course of migration of the Siberian 

 mammals, since they are not found in Southern Europe or in North 

 Africa. Hence one of the two alternatives must be accepted : either 

 some radical mistake has been made in the previous arguments, or 

 the Forest-bed is an Interglacial deposit, and contemporaneous with 



