[ 92 ] 



PLATE V. 



Fig. 1. 

 Arkloiv Dolerite. Magnification, 12 diameters. Ordinary light. 

 A, augite ; F, felspar (plagioclase) ; C, chlorite ; M, magnetite. 



Fig. 2. 



Ballintoy Olivine Dolerite. Magnification, 12 diameters. Ordinary- 

 light. 



0, olivine ; A, plates of ophitic augite ; F, felspar, generally 

 included in the ophitic augite ; M, magnetite. 



