PLATE XX V I. 
Fig. a. — Amygdaloidal aporhyolite. Specimen 48. Slide 48 D. Bigham copper 
mine. In ordinary light, X 30. Epidote fills the center of the amygdnle and quartz 
surrounds the epidote. 
Fig. b. — Amygdaloidal aporhyolite. Specimen G. H. W. Slide G.H.W. (unnum- 
bered). Eaccoon Creek, Franklin County. In ordinary light, X 30. 
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