266 K. JiMBÖ : 



The crystals from these different phices will be treated together 

 in the followins; lines : — 



The size of the individuals varies in thickness from about 

 0.1 cm. to more than 0.7 cm., as in the large crystals from 

 Onnadani. Observed crystal faces are c/= P co, oo P œ^ oP, co P, P cö^ 

 P, 2P, &c. The face of P So is usually hard to measure with the 

 reflection goniometer. Simple individuals are rare, and ordinary 

 twins on coP ^ with a sinsrle re-entrant ansfle are not numerous. 

 Most of the specimens are in the shape of simple looking penet- 

 ration-twins "with different faces on both poles. Sections paral- 

 lel to CO P CO show a characteristic subdivision into four sectors 

 of twinning individuals. Polysynthetic twins on co P öö aye 

 not rare ; when the thin wedge-shaped middle lamella of a tril- 

 ling is very small in dimension, the clinopinacoidal section ap- 

 pears like that of a simple crystal. In such a case different 

 arrangements of zonal enclosures in the two members of the 

 twin can be relied upon for tracing the twinning suture. 

 Hour-glass structure is often observed. Interpositions are very 

 numerous. 



The mother rocks of these black augites are either andésite 

 or its agglomerate. 



K0ZÔRI in Sano in Kai Province. — Hirabayashi, Takimoto 

 and others have collected green augite in a dark-green dyke- 

 rock piercing sandstone. The largest individual attains a length 

 of 4 cm. Observed faces are c/^F^, œ p œ, oP, ^ P, P, -P, 2P, 

 - 2P and 2P œ, among which 2P, - 2P and iPo; are small. The 

 most frequent combinations are ex» p, 00 P co. co p œ. P. Those 

 with oP besides are not numerous, also the three last mentioned 

 faces are often not found. Twins on c»Pœ are frequently ob- 

 served. A collection of these augite crystals is easily made from 



