172 BULLETIN OF THE MUSEUM OF COMPARATIVE ZOOLOGY. 
The occurrence of this keratophyre as a surface flow in close prox- 
imity to the large intrusive masses of elzeolite- sodalite- zircon-syenite 
of Salem Neck and the islands in Salem Harbor, and the augite- zircon- 
syenite of Marblehead and the Beverly shore, is interesting, as showing 
the various forms assumed here by the alkaline magmas under different 
geological conditions or at different periods. , 
June, 1890. 
