397 
monadnock, probably a remnant of the tertiary peneplain and near the 
level of the pleistocene peneplain which forms the “skyline” in this region. 
SCALE 20 st) 
Fig. 1. Map of Hill Pond, showing depth in inches at 10-ft. intervals when at the 
overflow point. 
The pleistocene peneplain is very much dissected in this locality. This 
particular monadnock is completely isolated, valleys having cut into its 
