4 io 
The Ohio Naturalist. 
[Vol. XV, No. 3, 
The region of Sandusky Bay and the islands is peculiar in 
many respects, being a meeting place of many species. The 
Sandusky area is apparently a biological island containing num¬ 
erous species heretofore not discovered in any other part of the 
state. The Sugar Grove area also contains a number of unusual 
isolated species but is not so sharply defined as the Sandusky 
Bay area. 
Important Geographic Boundaries in Ohio. 
There is a general transition belt between the eastern and 
western portions of the state, situated between the eastern limit 
of the Ohio Shale on the one hand and the glacial boundary and 
the limit of the higher hill country on the other. Sec Map I. 
The lake shore may also be considered as a more or less distinct 
plant area, but such details are not considered in this paper. 
