GEOLOGIC STRUCTURE OF THE RIUKIU CURVE. 31 



Fossils are not found in these rocks. I was able to collect specimens 

 of only a single species of coral from the limestone in Motobu, and 

 of an indeterminable Mollusca from the same liaiestone bed in the 

 neio;hbouring- island of Sesoko. 



The southern part of Okinawa-jima, which trends from N to S in 

 contrast with the princip;d Palœozoic region, shows a foundation of 

 Tertiary sediments. They were once entirely covered with raised 

 coral reefs, but these now remain only in scattered patches. The 

 Tertiary sediments are also exposed in the valleys of the Paheozoic 

 regions near Oyakawa. The chief Tertiary rock is a loose sandy shale 

 with thin layers of marl. Sandstones of a fine-grained brownish, and 

 of a hard bluish calcareous variety are sometimes found at Toguchi 

 near Ose, and a bluish shale near N^aha and Ose. Fossil wood 

 and a few species of small shells are found here and there in the sandy 

 shale. I have collected at Kochinda Leda, Drillia, Natica, Dentalium 

 octogoimui Lamk. and one other species of the last mentioned genus. 

 A number of Foraminifera, belonging to Operculum^ which is small 

 in size and not identical with the characteristic spscies found in 

 Diluvial reefs in the Riukiu Curve, have been gathered from the loose 

 sandstone in Okinaga near Itoman. The Tertiary rocks are either 

 quite horizontal, or inclined in various directions in contrast with the 

 regularly bedded Pnheozoic; as 



atNaba E— W N10,° or N60^E NW50° 



at Taira near S huri N80°E NW20° 



at Nakanishi (north of Naha) horizontal 



on the road from Shnri to Konaha N60°E NW40,° N60°E NW10°, 



N50=W SW50° 



at Konaha N40°E SE35° 



on tlie west of Yonabaru horizontal 



at Öse N45°\V NE5° 



atOlciuasa N40°E NW20° 



