Interglacial Periods. 5) 
the tundra below Dudino and beyond the present range of trees. 
Lopatim found recent shells of it, with well-preserved colours, 
9° further 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 freshwater clay of the tundra by Tolstoi Noss, 
Schmidt found Planorbis albus, Valvata cristata, and Limnea 
auricularia in a subfossil state ; Cyclas calyculata and Valvata 
ptscinalis he found thrown up on the banks of the Yenissei, and 
on a rotten drifted trunk, Limaw agrestis; Anodonta anatina he 
also found on the banks of the Yenissei as far as Tolstoi Noss, 
but no further. Pisidiwm fontinale still lives in the pools on the 
tundra ; as does Succinea putris on the branches of the Alnaster 
on the Brijochof Islands.” 
Mr. Belt mentions* that the Cyrena fluminalis is found in 
Siberia in the same deposits which contain the remains of the 
Mammoth and the Rhinoceros tichorhinus. 
“The evidence, then,” says Mr. Howorth, “ of the débris of 
vegetation, and of the freshwater- and land-shells found with 
the Mammoth-remains, amply confirms the a priori conclusion 
that the climate of Northern Siberia was at the epoch of the 
Mammoth much more temperate than now. It seems that the 
botanical facies of the district was not unlike that of Southern 
Siberia, that the larch, the willow, and the Alnaster were pro- 
bably the prevailing trees, that the limit of woods extended far 
to the north of its present range and doubtless as far as the 
Arctic Sea; that not only the mean temperature was much 
higher, but it is probable that the winters were of atemperate and 
not of an Arctic type.” (Geol. Mag. Dec. 1880.) 
The Mammoth Interglacial—lt need be a matter of no 
surprise that the climate of Northern Siberia during the time 
of the Mammoth was more mild and equable than now, if we 
only admit thai the Mammoth was interglacial. That it was 
of interglacial age is a conclusion which, | think, has been well 
established by Prof. J. Geikie and others. Into the facts and 
arguments which have been advanced in support of this con- 
clusion I need not here enter. The subject will, however, be 
found discussed at great length in Prof. Geikie’s ‘ Prehistoric 
Europe’ and in ‘ The Great Ice-Age’ (second edition). Mr, 
R. A. Wallace considers that one of the last intercalated inild 
periods of the glacial epoch seems to offer all the necessary 
conditions for the existence of the Mammoth in Siberia. 
That the Mammoth was interglacial will be further evident 
when we consider the climatic conditions of Europe at the 
* Quart. Journ. pate Soe. yol. xxx, p 464, 
