526 



Y.B. 164. 

 165. 

 166. 

 167. 

 168. 



169. 

 170. 



171. 

 172. 

 173. 

 174. 

 175. 



176. 

 177. 

 178. 

 179. 



Nepheline Basanite . 



Olivine Basalt . 



Ophitic Dolerite 



Ophitic Diabase 



Paisanite (Biebeckite- 

 Eurite) . 



Porphyrite 



Quartz : Uniaxial in- 

 terference fisfure. 



Quartz- A ugite-Diorite 



Quartz-Mica-Gabbro . 



Q uartz-Porphyrite 



Quartz-Porphyry 



Slate (Metamorphosed 

 Skidclaw, with Chia- 

 stolite) . 



Teschenite 



Teschenite 



Theralite . 



Volcanic Tuff 



Butterton Hall Pk., Staffs. 

 Linz a. Ph., Germany. 

 Saltcoats, N.B. 

 Moel y Gest, Carnarvon, 



Ailsa Craig, N.B. 

 Narborough, Leicester. 



Ben Cruachan, N.B. 

 Carrock Fell, Cumberland. 

 Lessines, Belgium. 

 Mynydd Mawr, Carnarvon. 



Quarry, Glasgow. 

 Quarry, Glasgow. 

 Quarry, Glasgow. 

 Saltcoats, N.B. 

 Bardon Hill, Leicester. 



