Proc. R.D.S., N.S., Vol. 5. 



Plate II. 



Fisr. 1. 



Veins of Felspar through Beryl. Section parallel to axis of hexagonal prism. Light polarized. 



( X 18 diameters.) 



Fis?. 2. 





Broken down BeryL Section near base of hexagonal prism of mixed Beryl and Orthoclase. 

 Polarized light. ( X 18 diameters.) 



Photo, from Nature, 



Photo-Ptd. by FORSTER & Co,, Ltd., DUBLIN 



