White. —Petrography of the Boston Basin, 
PLATE 2. 
Fig. 6. Eluidal texture. .Aporhyolite. Summit of Wampatuck Hill. (See 
Pl. 1, Eig. 5.) Slide 78, X 144. 
Fig. 7. Conglomerate. Near North Common Hill quarries. (See Plate 4 , 
Fig. 13.) Slide 204, X 4. 
Fig. 8. Ophitic texture. Diabase, showing lath-shaped feldspars. Dike on Pine 
Hill. Slide 203, X 4. 
Fig. 9. Opaque rings of alteration products, lining cavities in slate. Cut 
transverse to structure. Mill Cove. Slide C 15, X 4. 
