242 BULLETIN OF THE MUSEUM OF COMPABATIVE ZOOLOGY. 



The examination of the sections made from some of the narrow dikes 

 which cut the amygdaloid seems to show, in general, a simdarity to 

 either [Q. I'l or [6] - one series containmg undccomposed angite, the 

 other none that can be identified. The great cross dike is descnbed 

 under [Q. 8']. All of these later eruptive rocks seem in a more advanced 

 stage of decomposition than the amygdaloid. 



July, 1882. 



