of iiiicomformiibility, wliidi vcrv often form tlie very tup of tlie iliejier formation, 

 are indeed a very young and higli part of a system which iueludes all the ahovc- 

 nicMtioned tertiary licds and hasins of the slopes and witliin certain excavations 

 of tlie old sedimentary ro^'ks of the mountains encircling the vast plain which 

 is the (ibject of this memoir. 



This system is indeed a unit and does not exhibit uncomformahilities, nor 

 even very striking lines of partition. We are well euahled to ]i(]int out youni^ci" 

 and older strata in the thick succession of layers which it includes, hut only bv 

 the very fact that they overlie one another. The connexion of the shell-beds 

 of Tokio and its environ.s, with those of the environs of Sukegawa and other 

 places in the north of Mito, can also he very nicely traced along the road from 

 Tokio to Slito and larthcr northward. 



It deserves to be noticed that in no part of the plain of Tokio is any 

 trace of glacial deposits to be seen nor any trace of gracial action on any 

 of the formations. Of course we could not expect^ from what we know of 

 other countries, to find such traces in any but the diluvial formation, but 

 even in this formation we look for them in vain. This fact is fully admitted 

 by the author of the abo^-quated paper, Dr. E. Naumann ; he adds, however, 

 that there are certain signs of a lower temperature having existed during 

 that formation. I do not tljiuk those signs really exist. The Elephas, or 

 ifammoth, which is mentioned in Dr. Xaumann's paper, is not Elephas primi- 

 genius Blumenbach (see chapter 3rd), and so falls rather short of proving this 

 abatement of temperature, and the pre.sence of a few mollusca in the tertiary 

 beds which are now confined to the seas round the isle of Yesso — or even farther 

 to the north — gives of course still less evidence of a -lower temparature during the 

 (lilui-irtl epoch. Indeed this fact must be explained in a thorovighly ditierent 

 way since other fossils of the tertiary beds would rather seem to indicate a 

 higher temperature of tlie tertiary age. I have been always of opinion that it is 

 a little rash to draw conclusions from the presence of this or that species of fossil 

 j)lant or animal on t4ie climate of past ages. In most instances we do not 

 know till' animals or jilants themselves and are to form our conclusions on the 

 assnm|)tion of more or less strict affinity between them and surviving species, and 

 the case of Elephas primigenius and Rliinoceras tichorrhinus ought to have 

 shown sufficiently how erroneous such conclusions may turn out. Put even 

 when we know the plants an<l animals, we are not allowed to derive any definite 

 dates from their actual geograhical distribution. Professor Friuis, of Stuttgart, 

 one of the bebt tierman Geologists and well versed in researches of deposits of 

 many formations and climes, found on studying the prehistoric fauna of southern 

 Gennany— al)out50°of northern latitude— aconiple.\ of animals which remindetl 

 him of the colli ctions made for show, or in a zoological garden, lions, hyaenns 

 and other animals of southern latitudes east together with reindeer, and other 

 animals of frigid climates, ami with horses, stags, l«ars and many otlier animals 

 existing nowiulays in the same latitmlcs. All these species are lusserted to lia\c 



