278 K. jiMBo : 



126. Desmine and Epistilbite (?). 



A few specimens of bundle-shaped zeolite from Nikkö and 

 Ohara are probably desmine. At the latter locality we find, 

 besides, small flat crystals about 0.6 cm. long, and showing a 

 complicated division into sectors like the bundle-shaped specimen 

 of the same place. 



Small and very rarely observed specimens of flat prismatic 

 crystals, about 0.6 cm. in length, in the compact andésite of 

 Ohaea were measured on the prismatic edges and found to be 

 similar in crystalline habit to an epistilbite. 



127. Heulandite. 



Ogasawarajima. — Nearly colourless crystals of heulandite, 

 sometimes 2.5 cm. long (in the direction of the c axis), form 

 druses at this locality, together with the already mentioned white 

 apophyllite. The greenish tinge of this mineral is due to an 

 admixture of green particles along the cleavage. Crystal faces 

 observed in the specimens are oP, cc p oo, co p, -2P'ä) and iV^, 

 Cleavage-lamella shows as many fields as there are sides to the 

 section ; these fields make transition to the middle field. The 

 size of the middle field is larger in those lamellœ which have 

 been taken from near the surface of the crystal. The extinction 

 angle of each field is not constant even at the same tempera- 

 ture, a slight change of which produces a marked change in the 

 optical orientation. 



Ohara. — Yamasaki has described the heulandite of this 

 locality, which measures in larger individuals about 0.8 to 1 cm. 

 in length. Same crystal faces and optical anomaly, as in the 

 specimens from Ogasawarajima, are here observed. The mineral 

 is white and translucent. An analysis by Shinowara gave 



