öö B. KOTO : THE GEOLOGIC STKUCTURE OF 



minor fissures or lines of dislocation are oriented parallel and 

 also obliquely to the main line. The Strait of Sunda on the 

 west and that of Bali on the east are also transverse fractures 

 which separate the opposite islands by narrow channels. 



There are altogether 131 volcanoes, of which we may men- 

 tion the following six active ones ; Raun, Lemongan, Kelut, 

 Merapi in Solo, Guntur, and Gede, besides Semeru already 

 noticed. The explosion of Papandayang (? Gelungung) in West 

 Java in 1822 is celebrated for having destroyed forty villages 

 and left a large lake in their place. 



It is to be remarked in connection with the Javanese vol- 

 canoes, that the leu cite rocks, so rare in Asia, occur in the 

 island of Bawean, and in G. Ringgit in East Java. 



The Small Banda Group. 



The volcanic chain, hitherto traced, reaches its end in 

 Pan tar, and the zoological boundary established by Wallace^^ be- 

 tween Bali and Lombok seems to have no geological significance, 

 as is also the case of non-coincidence between the geological and 

 zoological limits in the West Indies. Lombok's neighbour is 

 Sumbawa, in which is located the vent of Tembora, the only 

 match for Papandayang in Java, and well known since its des- 

 tructive explosion in 1815, which darkened the sky over 3,000 

 miles. Floris^^ is volcanic, and its rocks are andésite and basalt. 

 The sedimentaries are tujffs and conglomerate derived from the 

 effusive rocks, and cemented by lime; the conglomerate gradually 

 passes upwards to the coral-reef limestone, the age of which is, 



8) Journal Royal Geogr. See. 1863, p. 231. 



9) Wiclimann, ' Bericht über eine Keise nach dem Indirichen Archipel.' Tijdschr. v. h. 

 Km. Nedeii. Aardrijksk. Gen., 1891, p. 92. 



