166 ART. 3. — B. KOTÙ: 



opened on the east, from which one can see the pumiceous bottom 

 through the densely grown shrub. 



Nabé-yama is a unique, widely-opened kettle hill, entirely 

 built up of stratiform loose lapilli and pumiceous mass. Therefore, 

 it is in a strict sense a true homate. The loose covering of éjecta 

 is in part no doubt of later origin. Hills like this both in form and 

 substance are not unfrequently noticed in submarine volcanoes, the 

 typical example being the new island near Iwo-jima on the south 

 of the Bônin islands, which rose on January 23rd, 1914 and later 

 disappeared. 



The reservoir of magma must have been near the surface, 

 not lower than 300 m.; the juvenile material being all lapilli and 

 pumice, formed and ejected by gaseous evolution in the magma. 

 Solid lavas have so far not been discovered, and a comparison with 

 those of the same eruptive period in other quarters of Sakura-jima 

 is impossible. 



h) The Yebino-tsuka Knob.— A hiUock {see Geologic Map, h n) which 

 lies to tlie east of Nabé-yama is an exact copy of the latter both 

 in form and material, differing only in size. The writer is inclined 

 to consider this pumiceous bocca to be of the same age as its 

 neighbor. This little hill, though half enclosed by the recent lava 

 flow, is so favorably and safely situated that all the visitors land- 

 ing on Kurokami went up and saw the recent terrific display of 

 vulcanism from there (Text-fig. 29, p. 143). 



B. The Byobu-hira Lava Field of 1476-'76. 



(Southwest Side.) 



PI. XVn. Figs. 6, 7, 8 ; PL XVIII. Fig. 1. 



a) Mode of Occurrence.— As the lava reservoir of the Bummei era 

 seemed not yet to have been exhausted in 1471, activity revived 



