CEPHALOPODA FROM THE HOKKAIDO. 



The present writer went to the Hokkaido mainly for the 

 purpose of settling the question of the relation of the Cretaceous 

 Ammonite-bearing deposits and the coal-bearing series, and was 

 there during four summer vacations from 1899 to 1902 inclusive, 

 thus having ample opportunities to make a valuable collection of 

 the Cretaceous fossils and also careful researches in the strati- 

 graphical order of the rocks. 



He proposes the following subdivisions of the Cretaceous 

 deposits of the Hokkaido, although the thickness of each division 

 has not yet been ascertained. Beginning from below, we have : 

 I. The lower Ammonite-beds Avitli Orbitolina-limesione. 



IL The Triffonia-a-dndstone. 



a. Lower Accuitkocer as- zone or Trlgonia longiloha-zowe. 



b. Theiis-zone. 



c. Pec tunc ulus-zouQ. 



HI. The ujiper Ammonite-beds. 



a. Upper Acantlioceras-zowe. 



b. Scaphits-heà^. 



c. Fachydiscus-heds. 



The upper part of the Cretaceous passes gradually into the 

 coal-bearing series. 



The layers of the Cretaceous complex are everywhere perfectly 

 conformable to one another and evidently represent a continuous 

 sedimentation. At the base of this formation, there is a thick 

 complex of shales and sandstones ; in it the former predominates 

 over the latter and contains in some places lenticular masses 

 of limestone with Orbitolina concava Lam.'* This complex is 

 what the present wiiter calls the lower Ammonite-beds. Above 



]) H. Yabe: 0/'6t<o/('/ta-Lime.stoue in the Hokkaido (in J:ip:incse). Joiirn. Geol. Soc. 

 Tokyo. Vol. VHI. No. üi. lyul. 



