90i> M. YOKOYAMA ; MESOZOIC PLANTS 



fossils occur. These s])eciniens, to2;ethei' Avitli those nlrendv in the 

 inu.seiiin of the Iinperia] University, Tokyo, form the snl)ject of 

 the following pages. 



]i>efore entering, however, into the consideration of tlie general 

 character of the above fossils, it may be well to give a brief account of 

 the geological nature of eacli locality in which plants are found. 



Tlie places whence I obtained my material ai-e the following : 



1. Kagahara, province Közuke. 



2. Yuasa, province Kii. 



3. Sakamoto, Fujikawa, and Tannö, in the Katsuragawa Imsin, 

 province Awa (Ashü). 



4. Kataji, Ishiseki, and Tôgodani, near Ivvoseki, province Tosa. 



5. Kaisekiyama, not far from SakaAva, province Tosa. 



6. Yoshida-Yashiki, near Sakawa, province Tosa. 



7. Chöja, in the Shiraishigawa-valley, province Tosa. 



1. Kagahara. 



In a long and narrow ]\Iesozoic depression in the northern part of 

 the Chichibu Mtmntains, commonly known as the Sanchu-Ditch, 

 there occurs a tliick series of shales and sandstones with suliordinate 

 layers of conglomerate. The greater pai-t of tliis formation was found 

 to bel(Mig to the (laulto-Cenomanian epoch. From beneath these 

 Cretaceous rocks, there peeps out, in the \'alley of tlie Hachimanzawa, 

 a set ot strata consisting of conglomerates in the lower part, and of 

 shales and sandstones in the upper. The .shales and sandstones 

 contain in their lower horizon innumerable remains of fresh-water 

 shells, of wdiich Cyrena forms the most important part. Plants occur 



1) Yokoyama. — Versteincninpcn auif der j(vpanitichen Kreide. Fahrcwtoçirapliica, vol. XXXVI, 

 1890. On some Cretnceoux Fossils from Shilcokic. Joxirnal of Coll. Sdeiire, lnqi. Cnir., Jajxiii, 

 vol. IV, lit. II, 1S91. 



