NOTES ON SOME IGNEOUS ROCKS OF JAPAN 



633 



of light-colored pumice. In their inner part the cellular structure 

 appears well developed, while the outer thin crust is usually 

 glassy and compact, strongly marked by cracks, which are char- 



FiG. 1. — View of the new dome from the east. May 11, 1909 (by T. Kawasaki, 

 Imp. Geol. Surv. of Japan). 



Fig. 2. — View of the new dome from the southwest, May 11, 1909 (by T. 

 Kawasaki) . 



acteristic of the so-called bread-crust bombs. This variety con- 

 tains well-formed anorthite crystals of considerable size, with an 

 average length of 13 mm. Beside these, there are not a few small 



