264 K. JiMBo : 



eilt of a dyke rock in the palaeozoic region of Hotsumura in 

 Tamba Province. 



106. Cordierite. 



Watarasegawa in Shimotsuke Province. — A detailed des- 

 cription of a cordierite trilling of white colour and very weak 

 pleochroism, was given by Kikuchi in the Journal of the Science 

 College of the Imperial University of Tokyo, 1<S89. In this 

 locality the cordierite is found only in hexagonal columns, which 

 are trillings with a distinct zonal structure and peculiarly dis- 

 tributed coaly substance. The crystals are about 0.5 cm. in 

 diameter of cross sections and are found in clayslate altered by 

 granite contact. An analysis by Shimizu is mentioned by 

 Kikuchi. 



Similar specimens of very minute size are found in the mica 

 clayslate of Sekinotsu in Omi and of many other places, which 

 are mentioned by Jimbö in the Geological Sketch of Hokkaido 

 and by Kikuchi in his paper on cordierite. Kameoka in 

 Tamba is a locality of green pinite alter cordierite trilling, Toki- 

 HAMA in Wakasa that of a pale micaceous substance in the same 

 form. Specimens from these two places are about 1 cm. in 

 diameter of basal section. 



Hussak has given a description of a blue-coloured, strongly 

 pleochroic, cordierite aggregates found in white porcelain- 

 like fragments. His specimens are from Asama volcano in 

 Shinano, while similar fragments were found by Yamasaki on the 

 volcano of Ganjusan in RikuchiÄ and by Ogawa on that of 

 NoRiKURA in Shinano. 



107. Bronzite. 

 Kikuchi has given an account of a green bronzite from 



