1872.] DAWKINS CLASSIFICATIOK OF PLEISTOCENE STExVTA. 435 



mostly of Pliocene descent, in the Forest-bed and in Rome, as Avell 

 as its more southern range, it must have been better adapted for 

 living in a temperate or comparatively warm climate than the 

 Woolly Rhinoceros. 



The third group, which was probably fitted for a temperate climate, 

 since it occurs neither in the north nor the south of Europe, con- 

 sists of 



Trogontherium Cuvieri. 

 Machterodus latidens. 

 Cervus carnutorum. 

 C. verticornis. 



Cervus megaceros. 

 C. Browni. 

 C. Sedgwictii. 

 C. Polignacus. 



The last species, like Elephas mendionalis, is a Pliocene ani- 

 mal which survived into the early Pleistocene stage, and has been 

 discovered by MM. Croizet and Jobert in the lacustrine deposit of 

 Mont Perrier, and identified by Dr. Falconer as occurring also in 

 the Forest-bed. Trogontherium Cuvieri and Cervus carnutorum 

 are found alike in the Forest-bed, and the deposit of St.-Prest at 

 Chartres, while the Maclicerodus latidens, of Kent's Hole, is found 

 as far south as Auvergne and a cave in the Jura. The Irish Elk 

 ranges, in space, from Scania as far as the valley of the Po — and in 

 time, from the Forest-bed era down to the prehistoric peat-bogs, 

 being far more abundant in the Prehistoric than in the Pleistocene 

 strata. It has not, however, been discovered in the latter further 

 north than Quedlinburg, on the Continent, and Kirkdale cave, in 

 Great Britain, although in the prehistoric deposits of Scania it is 

 comparatively abundant (Nilsson, MSS.). 



13. The Theee Climatal Zones. 



The inference as to the Pleistocene climate of Europe drawn from 

 the range of the Pleistocene species which are still living is corro- 

 borated by an appeal to those which are now extinct ; and, treating 

 the whole mammalian land-fauna as one, we have three great climatal 

 zones, marked out by the varying range of the animals — the northern 

 (see Map, p. 436), into which the southern forms never penetrated, 

 the southern, into which the northern species never passed, and an 

 intermediate area in which the two found are mingled together. The 

 latitude of Yorkshire is the extreme northern boundary which the 

 southern forms never passed ; and a line passing through the Alps 

 and the Pyrenees is the limit of the range of the northern animals, 

 properly so called. In the head quarters of the Reindeer and Musk- 

 sheep in Scandinavia and Northern Russia, the climate must have 

 been like that of those regions which they now inhabit ; and in the 

 head quarters of the Rhinoceros etruscus, E. meridionalis and E. an- 

 tiquus, of the Spotted Ilysena, and the Hippopotamus it was most 

 probably hot. In the following map the three zones are marked, the 

 northern by horizontal, and the southern by vertical broken lines ; 

 while the intermediate area, in which the northern and southern 

 animals were associated together, is represented by the crossing of 

 the lines. 



