of Portland, Dodge county, Wisconsin. 285 
eastern exposures are on a corresponding low ridge farther to 
the east, and are of less extent. 
_, The rock is almost entirely quartzite. In a few places I 
found outcrops of a metamorphic conglomerate like that ob- 
served in Sauk county, and in still fewer places very thin 
seams of a talco-siliceous schist are visible. I found none of 
7 
