ARCTIC INTERGLACIAL PERIODS. 183 



the Ural Mountains, in a place where larches now only 

 grow in sheltered river- valleys, in turf on the top of 

 the tundra, prostrate larch trees still bearing cones." * 



Schmidt also states that he was informed that at 

 Dudino, just at the limit of the woods, there had been 

 found in a miserable larch wood the lower part of a 

 stem sticking in the ground, apparently rooted, which 

 was three feet in diameter. He also states that, 

 "eleven versts above Krestowkoje, in lat. 72°, he 

 found, in a layer of soil covered with clay, on the 

 upper edge of the banks of the Yenissei, well-preserved 

 stems like those of the birch with their bark intact, 

 and sometimes with their roots attached, and three to 

 four inches in diameter. Professor Merklin recognises 

 them as those of the Alnaster fruticosiis, which still 

 grows as a bush on the islands of the Yenissei, in lat 

 70J° N." . 



Evidence from Shells. — In the fresh-water deposits 

 in which the bones of the mammoth are found, there 

 are fresh- water and land -shells, which indicate a 

 warmer condition of climate. I quote the following 

 from Mr. Howorth's memoir : — 



"Schmidt found Helix scJirencki in fresh- water 

 deposits on the Tundra below Dudino and beyond the 

 present range of trees. Lopatim found recent shells 

 of it, with well-preserved colours, 9° farther south, in 

 lat. 68° and 69°, within the present range of trees, at 

 the mouth of the Awamka. The most northern limit 

 hitherto known for this shell was in lat. 60° N., where 

 they were found by Maak in gold-washings on the Pit." 



" In the fresh-water clay of the Tundra, by Tolstoi 

 Noss, Schmidt found Planorbis albus, Valvata cristata, 

 and Limntua auricvLaria in asub-fossil state; Cyclas 

 ccdyculata and Vcdvtda piscinalis he found thrown up 



* Schmidt, as quoted by Howorth. 



