from the iilenfity of the Tokio pliocene stmta^ und tlip «VBtein of RniidMone, 

 sh:ili> &o. anioiiiitiii'^ at leiu^t to some hiindn'il nit'tei-n in tiiicknt'ss. Tliii« vorv 

 thickness, tlcirly sliown liy the (Jliicliibti-liiyon« as will as l)y tliiwc of Ilitliclii 

 ami otlior proxMiices, and still more tlio hif/h nnijh: of >lij>ping oAuii »»Iwervetl, 

 foiliiils the inchisioii of thfsc strata within the coin pass of the (|nat('ninry fonna- 

 tinn. Now. not l)ein;; able to claim a ([tiatt^rnary -.vfi' for thi^s<; larj;i.' systems «if 

 rocks, we catHKit do so for the f'ji ri>cks and llicir ]i;inillc!s in llu' Tdliii) 

 plain. 



The solution of this prohlem is of the highest importance for <laiKUiC8ti 

 ((»•olojjy. 'J'lic strata in 'piestiun occur aluifist every wiiere; at least in almogt 

 all the provinces ami distriits which thus far have li;.'en e.xplorcd. Wo iiti I 

 them, with or without other selimentiiy or volcinic or cry.stallino ru:lcs, not 

 only along tho coist, but oftan far into the interior. Their geological age oscer- 

 tiiined, we have a fi.'ce«! jMiint fri>m which wc may advance, and without which 

 we should scarcely have a sufficient basis for oliservation anywhere. This is true 

 as well in regard to the underlying strata, tertiary, for instance brown coal, 

 mesozoic, pahezoic or azoic, as to all the eruptive formations and to the 

 overlying quaternary strata which give the surface-fonnation of wide dibtrict«. 

 The largest of these is the i)lain of 7ot('o, whoso geology could never be fully 

 imderstood without a strict determination of the fossiliferoiis deciier layer« of it« 

 environs. — 



This point lieing settled, I may add a few remarks alh>nt the geological 

 changes which, since the origin of those oldest dejHisits of the Tokio plain, arc 

 to l)e oljscrved within this district. 



The character of the fauna may 1* dismis.^^ed alter all that has Iuh'U said 

 about it here and in the introductory chapter. I repeat only that the marine 

 fauna also gives evidence to a highly satisfactory degree of its jmlaearclic 

 character. The molluscous fuima of Japan is much more closely connected with 

 tho European fauna than we should have ever exjiected without recurring to 

 tho fauna) of past ages. This crmnection is mticli too intimate to lie accountetl 

 for by the ."nnall number of 'circumpolar' sjwcies cont^iined in the Jainnew 

 faima; but it is well explained by the close affinity which the pliocene fauna 

 reveals with the European. It has, therefore, a far greater im|Mirtanco than it 

 would have if it Wius an isolated faunula and not— as it i.s— a jxirt of a very large 

 fauna which, in certain respects, has been better preserve«! iu Jajian than in the 

 other parts of the jmhearctic region. I need lait call the rc-uler's attentitjn to 

 the important fact that the jiliocene Nucula Cobboldi.-u actually exist« in the 

 ocean encircling Japan. 



As the qiicstion about the teniiierature has also been settled in the first 

 chapter, I may jirocecd to the liust object of these luigi*, to the question con- 

 cerning the changes of the level of the sea. 



Of cour>e there can be no doubt whatever about the fact that since the 

 deposition of the pliocene strata the land ha« Ijcen slowly elevate»! alx»ve the level 



