156 OHIO STATE ACADEMY OF SCIENCE. 
the edge of the water-lily zone at a depth of two feet to water 
about one-half foot deep. At the north end it is twenty-four feet 
wide and on the west side about fifteen feet. It is most perfectly 
developed at the north end (Fig. 2), where Rumex verticillatus 
L., Polygonum amphibium [L,. and Polygonum emersum (Mx. ) 
Fig. 2. North end of the Lake, showing plant zones. The Half-sub- 
merged Zone and Decodon Zone are not well marked in the picture be- 
cause of the undeveloped condition of the latter. (Photograph taken June 
IS, 1902.) 
Britt. are the characteristic species. On the east and west sides, 
owing to more typical uliginous conditions, Typha latifolia L. 
and Sparganium eurycarpum become prominent. On the south 
