3°4 
The Ohio Naturalist. 
[Vol. VIII, No. 6, 
or pond. On Cedar Point, however, the elevation of the habitat 
of the various zones due to the accumulation of vegetable matter 
muse to some degree be counteracted by the general rise of the 
water table consequent to the cumulative rise of water in Lake 
Erie,—2.14 feet per century. It seems likely that, in some cases 
at least, the general movement may be reversed as to the con¬ 
centric vegetational formations, so that they may move away 
from the central portion of the depression; thus, from habitats 
more hydrophytic to less hydrophytic ones. 
At the northeast corner of Cedar Point sand is rapidly accum¬ 
ulating along the shore to the south of the Jetty Protection or 
Breakwater and a lagoon is now (1907) being segregated from the 
Lake near the old light-house building. There is at this place a 
considerable indrifting of organic drift debris of various sorts so 
that the vegetation shows somewhat more of an affinity to that 
of a humus marsh or pond than is usual in beach lagoons. The 
initial stage here appears from the studies given it (1905-7) to 
be essentially as follows: 
Stage A. 
a. Potamogeton Formation. 
b. Populus-Salix Formation. 
The Potamogeton Formation. 
Facies: Potamogeton pectinatus. 
Secondary Species: 
Vallisneria spiralis, Potamogeton natans, etc. 
The Populus-Salix Formation. 
Facies: Populus deltoides, 
Salix cordata. 
Secondary Species: 
Salix jragilis (’), Salix lucid a, 
Cakile edentula, Strophostyles helvola, 
Xanthium commune. 
This latter formation may be considered as identical with the 
beginning of a Populus-Salix Ridge Formation but, under the 
conditions leading to the development of a sand ridge, the 
willows soon disappear while, under the more uniform condi¬ 
tions leading through the different stages of a lagoon succession, 
the willows are relatively quite important. 
In the lagoon succession at Presque Tsle the second stage 
shows the following structure, this appearing to be typical also 
for the Cedar Point succession, although somewhat mixed in the 
lagoon under discussion: 
Stage B. 
a. The Potamogeton Formation. 
b. The Juncus-Eleocharis Formation. 
c. The Populus-Salix Formation. 
