178 



PROCEEDINGS OF THE ACADEMY OF 



[Part I 



Fig. 5 



Fig. 6 



Fig. 7 



Fig. 8 



Fig. 5.^ — Albite, Garrison's quarry, west of Rock Springs, Cecil County, Mary- 

 land. Crossed nicols, x 15. 



Fig. 6.-— Albite, showing both albite and pericline twining. One mile southwest 

 of Nottingham, Chester County. Crossed nicols, x 15. 



Fig. 7. — Albite (black), anorthoclase (twinned), and quartz (white), one and a 

 half miles northwest of Sylmar, Chester County, Penna. Crossed nicols, 

 xl5. 



Fig. 8. — Aggregates of zoisite (gray in center), in serjientine (white groundmasf) 

 through which are dispersed needles and blades of actinolite (dark). One 

 and a half miles northwest of Sylmar. Plain light, x 15. 



