210 Dr. H. Yabe — Neic Pleistocene Fauna from Tokyo. 



IV. — A New Pleistocene Fauna from Tokyo, with a General 

 Statement on the Pleistocene Deposits of Tokyo, Japan. 



By Dr. H. Yabe, Geological Institute, University, Tokyo, Japan. 



JUST before my departure from Tokyo to Europe, in 1908, my 

 attention was called, by the kindness of Mr. Gordon Yamakawu, 

 to a fossil fauna from a catting along the Yamanote line of the 

 circum-Tokyo railway, near the Tabata station. It was seven years 

 ago, when the railway line was still in process of construction, that 

 Mr. Yamakawa formed a collection of fossils, consisting exclusively of 

 molluscan remains. Of special interest is the abundant occurrence of 

 Tellina venulosa, Schrenk, in the shell-sand, and as its presence is 

 really of exceptional interest in the environs of Tokyo we visited the 

 place together soon afterwards. The present brief account is contributed 

 partly for the purpose of recording the observations of this diligent 

 young student of fossils, whose lamentable and too early death took 

 place last autumn, during my absence in Europe, and partly with the 

 intention of interesting others in the further study of the Pleistocene 

 and Pliocene geology of Tokyo, which though apparently quite simple, 

 contains many interesting and unsettled geological questions. 



The surface of Tokyo is topographically divisible into two parts : 

 higher terracedand and lower alluvial plain, as very well expressed by 

 our plain terms Takadai and Shitamachi. The change from the first to 

 the second is usually abrupt, with the average difference of 15 metres in 

 height, and marked by a series of nearly vertical bluffs ; for instance, 

 the ridge connecting Ueno and Asukayama is merely the vertically cut 

 end of the terrace land, which trends S.E.-K.W., and faces JN\E. 

 Along the very foot of the ridge lies the Owu line of railway; the 

 above-mentioned Tabata station is situated about two miles JN\W. of 

 Ueno, and there the Yamanote line branches out from the Owu line 

 and enters into a cutting through the terrace land. The fossil locality 

 visited by us is situated just in the entrance to this cutting. 



The greater part of the cutting, about 12 metres in height, was 

 already grass-covered, but evidently consisted of loam and the under- 

 lying thick sandy gravel bed. The latter was succeeded by a bed of 

 brownish sand, about one-third of a metre thick, which is very 

 variable in character and liable in a short distance to pass into an 

 argillaceous sand or an arenaceous clay. The remaining lower part of 

 the cutting, about 2 metres in thickness, was already to our great 

 regret enclosed by a stone wall, just at the spot where Mr. Yamakawa 

 had made his collection of fossils ; at a little distance from the spot, 

 however, we could actually examine brownish arenaceous clay, full of 

 vertical pipes, exhibited on the same level as that of the recently 

 exposed and now hidden shell-sand. This arenaceous clay passes 

 gradually upward to the above-mentioned brownish sand; no marked 

 stratigraphical boundary is recognizable between these. That the 

 distribution of the shell-sand was confined to a very limited area was 

 also obvious from the present widely scattered remains of the once 

 excavated fossil shells over the floor of the cutting, and also in an 

 open drain. 



Only 200 metres or a little more distant from the place are two, 



