<)Q Vol, XLIIL, Art. 6. — S. Tsuboi: 



Pole's hair or glass cotton, found and collected by Naka-MURa in 

 1907 between narrow crevices of lava in the central Mihara^^ 

 crater. This is the only specimen ever found in our country. 

 History records the fall of Pele's hairs during the eruption on 

 August 31, 1777 (p. 56). 



13) Micro-aUivalite. (PI. IV. Fig. 5.) 



At the foot of Kazahaya'^ (la), imbedded in an ash layer (PI. VI. 

 OA 12) between the lavas of olivine-bytownite-basalt (p. 92) which 

 constitute a small igneous body, the writer found a coarse-grained 

 holocrystalline block, about 3 cm. across, which is petrographically 

 identical to that ejected in the eruption of Sakurajima^^ in 1914, 

 at the southern extremity of Kyùshû, described by Kotô^'* under 

 the now name of " micro- allie dlltß."' Specimens of similar motex 

 were also collected by Tsujimura on Miyakejima'''', one of the Idzu 

 Islands. 



Tlie block may be what Lacroix calls " enclaves homœoghies " 

 or IIarker calls " cognate xeaollth.'" The writer's view on tho 

 genesis of this phanerocrystallino mass will be given later (pp. 

 121-122). 



Our micro-allivalite consists of anorbhite and greenish olivine, 

 each graia ranging in diameter from 1 to 5 mm. 



Anorlhitc hsis the refractive indices: «< 1.575 1. 58 !</?< 1.584 

 1.583 <r, so that the chemical composition of the mineral is inferretl 

 to bo Ab^Augg. It is twinned according to Carlsbad, albite, pericline, 

 and Manebach laws. 



1) HM 2) iLf. 3) mm 



4) "The Great Eruption of Sakarajimii in 11)14," Jüur. Set. Coll. Lap. Unio. Tôlcjô, Vol. 

 XXXVIII., Art. 3, p. 195, 191G. 



5) S-t^^ 



