AKT. 2,-S. YOSHIWARA; 



6. — Uninhiil^iteil Islands in Kiukiii 54 



Tlir liorodino Group 54 



The Finnacle Group 55 



7. — Uninhabited Islands lyin}< to the North of Formosa 56 



PART IV. (tEOLOGY of NOKTH FORMOSA 57 



PART V. CONCLUSION 63 



PART I. -Introduction. 



The Hiukiu ('arve.! consisting of all the islands lying between 

 Kyüshü and Formosa, belongs partly to the Riukiu Islands and 

 partly to the Province of Osumi; and is in all respects very little 

 known. As for the geology of these islands, no reconnaissance 

 survey of them had been made prior to the trip, the results of 

 which this pa})er embodies. On the other hand, Formosa, our 

 new territory, has been studied by many geologists, îind the 

 results of their studies have been partly published. Our Imperial 

 University has sent in the last five years several naturalists to Formosa. 

 Among them were Profs. P>. Koto and M. Yokoyama, who made 

 geological observation, the former in 1897 and the latter in 189<S. I 

 was sent to visit Kiukiu and Formosa, for the purpose of ascertaining 

 their geological C(^nnection. After a trip of about one month in the 

 northern part of Formosa, I spent nearly hfdf a year (from July to 

 December 1<S91)) in travelling through the Riukiu Islands. With the 

 kind assistance of the officers of the Okinawa Prefecture (the local 

 government of Riukiu), 1 was able to visit nearly all the islands, which 

 are about (55 in number. Only Kume-jima, Aguni-jimâ, Tonaki-jima, 

 ïori-shima, the Iheya subgroup, the very small uninhabited islands, 

 and some islands in the Kerama subgroup have not been studied. All 

 of these, however, have been visited by others, who have furnished me 



t This name has been proposed by Prof. B. Koto. {The Journal of the Gcol. Soriet)/ of Tôki/ô 

 Vol. V, No. 49, 1897.) 



