90 
A. J3. Edwards. 
Plate I. 
tig. 1. Alierophotograph of typical two-pyroxene dolerite. In ordinary light. Xlo. 
lig. 2. T\vo-i)yroxene andesine-basalt, in ordinary light, showing the pyroxene laths in 
the glassy base, and an olivine niicrophenoeryst. Xl5. 
