PLATE XLYI. 

 Fig. a. 



(Sp. No. 23353. With analyzer, x 90.) 



Wehrlittf, There are shown in this illustration the zones of orthorhombic pyroxene and horn- 

 blende which lie between the olivine and feldspar. (Described, p. 255.) 



Pig. B. 



(Sp. No. 23353. Without analyzer, x 90.) 



Wehrlite". The ramifying feldspar growths in the hornblende can be seen better when the 

 section is, viewed with the analyzer in, as in fig. A. (Described, p. 255.) 



322 



