PLATE XXV; 
Fig. a. — Rhyolitic structure in an aporhyolite. Specimen 153. Slide 153. South 
Mountain. In ordinary light, X 120. Aschen-structur of Miigge. 
Fig. 6. — Piedmontite in an aporhyolite. Specimen 162. Slide 482. Southeast 
flank of Pine Mountain. In ordinary light, X 120. 
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