156 BULLETIN OF THE 
be deemed in its nature paroxysmal. It therefore becomes necessary to 
make a very careful inquiry into the value of the evidence which this 
case affords as to the speed with which these changes of level wcre 
brought about. This problem should be considered by many field 
geologists. It caunot adequately be solved by one student. On this 
account, I venture to present the arguments in the case of the Florida 
lake district, with the hope that they may be carefully reviewed by 
other students. 
