PLATE XXVII. 
Fig. a. — Amygdaloidal aporliyolite with tridymite spherulites. Specimen 276. 
Slide G. H. W. Eaccoon Creek, Franklin County. In ordinary light, X 30. 
Fig. b. — The same. Specimen G. H. W. Slide G. H. W. (unnumbered). Raccoon 
Creek, Franklin County. In ordinary light, X 30. 
120 
