White. — Petrography of the Boston Basin. 
PLATE 1. 
Fig. 1. Contact between slate (on the left) and granite (on the right), showing 
sharp demarcation and slight contact zone. North Common Hill. 
Slide C 14, X 81. 
Fig. 2. Coarse granitic texture. Hornblende granite. Rattlesnake Hill. Slide 
72a, X 4. 
Fig. 3. Fine granitic texture. Hornblende granitite. Weymouth Fore River. 
Slide C 2, X 4. 
Fig. 4. Porphyritic texture. Porphyritic aporhyolite. Near Wampatuck 
Hill. Slide C 10, X 4. 
Fig. 5. Aporhyolite showing orthoclase crystals and flow texture. Summit of 
Wampatuck Hill. Slide 78, X 4. 
