79 



All these strata of shale, sandstone, hard and loose conglomerate have, as 

 is repeatedly stated, an enormous thickness and yet a perfectly uniform fauna. 

 And this fauna is eminently the same as at Oji, Takigasliira etc. 



The results given at the end of the 7th chapter show that in the localities 

 first mentioned, Chichihn, Shiuano, Mino, altogether 44 species have been found 

 which belong to the fauna of Oji, Tahigashira &c., and that there are otdy 7 

 new species; whilst in Hidachi 36 species from Oji, Takigasliira etc. and 14 new 

 ones have been found. But Hidachi, on the other hand, is closely connected 

 with the other localities by the identity of 30 of the former and 7 of the latter 

 species, and thus, only 7 species remain peculiar to Hidachi. These 7 species 

 are all of them living in the Japanese sea, and it is a remarkable fact that the 

 separate basin near Sukcgawa, richest comparatively in such species as do not 

 belong to the fauna of Oji and Takigashira (3 among 7), has not one species 

 which is not found living near Japan. All the other localities, and the more 

 distant places, have proportionally very few species (if any) not belonging to the 

 Tokio fossil fauna; and all of them together with Hidachi have only one species 

 which is neither found in the fossil fivuna of Oji etc., nor among the living shells 

 of Japan, viz. Turritella communis Kisso. As the proportion of fossil Tokio 

 shells belonging to the living Japanese marine fauna to those which are extinct 

 in Japan is 69 to 18, the latter being 21 percent, the presence of one further species 

 of the latter description with 13 new species living in the neighbourhood would 

 rather serve to jirove a younger age of the sandstone, conglomerate, marl and 

 shale. As this cannot be admitted, the Tokio layers being undoubtedly one of 

 the higher, if not of the very highest parts of the younger tertiary formation of 

 Japan, we are forced to regard both layers as most intimately united. 



A further division of the entire system cannot be made, at present, pal;\3- 

 ontologically; we must confine ourselves to separating it into upper and lower 

 strata simply according to their relative position. 



Tiiere can be no doubt about its very young age, and the Pliocene Era, 

 or the Crag-division of the tertiary formation, is the only one to which we can 

 assign it. If the question should arise whether we should assume that it belongs 

 to the miocene formation, this is answered in the negative by the absence of a 

 somewliat larger number of extinct shells, by the scarcity of typical miocene 

 species (though there are some present, for instance Columbella scripta, Chemnitzia 

 elegantissiina, Eulima subulata, Dentalium entale, Lucina borcalis, Diplodonta 

 trigonula, rectnnculus glycimeris, to which perhaps some other, for instance 

 Panopaea generosa and the Tornatina might be added), by the close resemblance 

 to the Crag and by an approach which tho.se layers make towards the diluvial 

 deposits. 



With these, however, they cannot be identified for the reasons given at the 

 beginning of this cha[)ter — cliaraiMer of fauna, high percentage of species foreign 

 to tlio present marine fauna of Japan, line of nnconfm-mabijity lietween them 

 and doubtless lower diluvial strata—, and besides for those reasons which result 



