3 IO 
The Ohio Naturalist. 
[Vol. VIII, No. G, 
of the facies into definite structures the Cephalanthus occiden¬ 
talis Consocies occupies the part of the habitat adjoining and 
grading into the Decodon-Persicaria habitat, while the other two 
facies alternate with each other in the outer more mesophytic 
part of the habitat. The formation is here bordered by a shrub 
formation which is approaching old age and which may more 
properl\- be regarded as a bordering thicket associated normally 
with the Calamagrostis Wet Meadow Formation. 
Thicket Formation. 
The Rhus hirta 
Facies: Rhus hirta. 
Secondary Species: 
Cornus amomum, 
Salix cordata, 
Salix amygdaloides, 
Vitis vulpina, 
Dryopteris thelypteris, 
Cornus stolonifera, 
Salix nigra, 
Salix lucida, 
Parthenocissus quinquefolia, 
Rubus nigrobaccus. 
This formation apparently displaces the Salix ( spp .) Forma¬ 
tion where dryer and more mesophytic conditions are approached. 
This also represents a consocies of a more northern formation 
which on Presque Isle was of considerable importance and was 
there designated as the Rhus-Alnus Thicket Formation. 
The Ulmus-Acer Forest Formation. 
There are evidences that this formation will come in instead 
of the Quercus velutina-inibricaria Forest Formation in the zone 
first occupied by the Populus-Salix Formation. The elevation 
of the water table and the consequent hydrophytic tendency of 
this habitat probably has something to do with the exclusion of 
the oak forest from this zone. Where the cotton-woods have 
built up a steep ridge in close proximity to the water, as on the 
east side of the Lily Pond, the vegetation will, of course, be more 
xerophytic and will follow the stages as indicated for the ridge 
succession, finally passing into the oak forest and this will not 
pass into the Ulmus-Acer forest until considerably more meso¬ 
phytic or even semi-hydrophvtic conditions prevail by the 
accumulation of much humus or by the rise of the water table, 
or both. 
To the southwest of this pond thei'e is a small narrow pond 
almost choked up with vegetation, the whole being somewhat 
further developed in its successional stages. The Cephalanthus- 
Cornus Thicket Formation is strongly developed and, in the 
course of a few years, unless the rise of the water is too rapid, 
the shrubs will have occupied the whole central portion of the 
depression. 
Previous to the construction of the artificial canals or “La¬ 
goons” in connection with the amusement features of the pleasure 
