4 ART. I.-S. YOSHIWAKA: 



low remains oï ancit-nt fringing- reels built upon tlie Pakeozoic sedi- 

 ments. Tlie northern hall" of Taketomi-jima is composed of Palaeozoic 

 rocks, chieÜy of compact quartzite ; but the southern half is covered 

 entirely with a flat layer of raised reefs about 30 ft. in thickness. The 

 raised reefs of Hatoma-jima, also about 30 ft. thick, completely sur- 

 round a small Tertiary hill called Xakamori, which is situated in the 

 center of the island and has an elevation of 117 ft. Kuro-shima, 

 Aragusuku-jima and Hateruma-jima are all entirely made up of the 

 raised reefs, the highest point of the last named island being 220 ft. 

 The others attain an elevation of only 30 to 40 ft. 



Ishigaki-jima, at the time of the formation of the raised reefs 

 probably consisted of four small islands (PL II A. B. C. D), near 

 which the frinirinof reefs were built. The fundament of these reefs 

 evidently consisted of Palaeozoic rocks, Tertiary limestone and sand- 

 stone, and the andésites, as they are now seen directly underlying the 

 reefs which show no sign of disturbance since their formation. The 

 distribution of the reefs is in three great groups. The first group is in 

 the southern part of the island. It is widest in area occupying the 

 coast reg-ion for about ten miles with a breadth of about tAvo miles. 

 The reefs form three successive terraces, the uppermost of whicli 

 attains an elevation of about 100 ft. above the sea-level. This terrace 

 extends from the northern part of Shiraho-mura to the neighbourhood 

 of Moriyama-mur.i. The second terrace, 20 or 30 ft. lower than the 

 first, extends from the vicinity of Miyara-mura to the southern foot of 

 Banna hill. The third or lowest terrace is found along the shore near 

 Shika-mura and other villages. The second group was develoj^ed 

 along the shores of the two supposed islands (C and D) which are 

 situated to the north-east of the (others (A and B). At the present 

 time we see the table-land of Palœozoic rocks covered wûtli coyü\ reefs 

 20 to 30 ft. tliick along the eastern and western coast of Ishigaki-jima, 



