122 
ALASKA GEOLOGY 
represented on the Alaskan coast and many of the species 
might be dredged to-day in the channel near Douglas 
Island, still there are three or four which are not now 
found, except considerably further north; and the condi¬ 
tions under which this fauna existed were doubtless meas¬ 
urably colder than at present in the same locality. 
