JIMBo : GEOLOGY OF JAPANESE SAKHALIN. 9 



(2.) Gray sandstone with Pectcn Peckhami (Merei). and gray tufaceous shale 

 with small shells of the same species (Kushunnai). 



(3.) Gray shale with Thyrasia bisecta (Shiraraka and Tomarionnai). and 

 with Echinarachnijts sp. (Takinosawa) ; and greenish-gray shale with Tellina sp. 

 (Mauka and environs). 



(4.) Gra\ tufaceous shale (** Kushunkotan Shale ") with an inflated form of 

 Yoldia, showing a \ er\- wide distribution, as for instance at Korsakoff and its 

 vicinitv\ 



(5.) Gray sandstone with several species of MoUusks (Wenruesan, Porotomari, 

 etc. near Ushoro ; and other places). 



(6.) Dark-gray marl with sponge remains (Peshuturu). 



(7.) Soft graj' sandstone with Alya crassa (the lower course of the Xaibuchi 

 river), and similar sandstone with large shells of a large-eared species of Pectcn 

 fthe same locality- and Peshuturu). 



Kawasaki endeavoured to subdivide the Tertiaries of Sakhalin, without 

 taking the difference of fossil contents much in consideration, (see liis report, p. 

 16-17;. 



\\ hether the above enumerated beds are really independent of one another 

 can not yet be definitely answered ; but we must remember that many fossil forms 

 are also met with in Hokkaido. Thus. Thyrasia bisecta occurs at Mörai in 

 Ishikari province, and other places ; Echinarachniiis at Kanikarushi in Hidaka. 

 the inflated Yoldia in the oil-field of JNIörai. and at Wakkanai in Kitami ; Mya 

 crassa at Penaanrubeshbe in Tokachi. and Pectcn Peckhami at Yüdö in the same 

 province. The numerous Molluscan species of W enruesan and other places will 

 correspond to those in the shell bed of Piratoriushnai in 'Hidaka. 



The Quaternary rocks in Sakhalin are clays, sands, gravels, and peat. The 

 young deposits composing the coast terraces sometimes attain a great thickness 

 of more than 60 meters. Gold placers were discovered mostly in the valleys of 

 Palaeozoic regions. \'olcanic detritus may be met with on the slopes of the 

 conical mountains of Ushoro. but it has never yet been actually obser\"ed by us. 

 anj-where in the island. The deposits of sea-terraces, which usually level 

 the irregular surface of underlying hard rocks, sometimes lie upon the well-shaved 

 horizontal face of rocks, as at Ochopokka and other places. This fact is of 

 special interest in connection with the shift of sea-level in past j^eriods. when we 

 remember the extensive development of submarine shelves on the present sea- 

 coast, especial]}- in the regions of Tertiary- rocks. 



The formation of thick j^eat underneath the still growing mosses and lichens 



