478 



MEASUREMENTS OF CRYSTALS. 



aUARTZ. (Continued.) 



Figs. 139 and 140. Twin crystals from 

 Catskill, Greene county. The latter 

 also occurs in Herkimer county. 



Fig. 148. A twin from Middlevillc, Her- 

 kimer county. 



(The measurements will be found on 

 page 476.) 



