451 
several feet in depth. In the late summer and fall this area is either 
entirely dry or with only a few shallow pools distributed over the 
surface. Scattered over the marsh are numerous forest islands 
from fifteen or twenty feet to over two hundred feet in diameter. 
Some of these are irregularly round in outline; the largest ones, 
however, are of an oblong shape. 
There are three distinct plant societies in the marsh, which may 
be characterized as follows. 
I. THE FOREST ISLANDS SOCIETY. 
Populus tremuloides. American Aspen. 
Ribes floridum. Wild Black Currant. 
Salix longifolia, River-bank Willow. 
fi) La hy PEAS LATIROLIA SOCIETY: 
Cattails surround the forest islands, often reaching a height 
of ten feet or more, presenting an almost impenetrable jungle. In 
several places small areas of cattail islands occur, and the ditches 
and streams are lined with Typha. 
III. THE IRIS VERSICOLOR-CALAMAGROSTIS CANADENSIS SOCIETY. 
The greater part of the swamp is covered with these two plants, 
interspersed here and there with clumps of Sagizttaria latifolia, 
Sparganium eurycarpum, Sium cicutefolium and Eupatorium pur- 
pureum. 
The bluejoint grass (Pl. VIII., 2) reaches a height of eight feet or 
more, affording excellent concealment for the nests of marsh-inhabit- 
ing birds. 
THE FAUNA OF THE MARSH. 
INSECTS. 
With the addition of a few small beetles in the fall, the insect 
fauna of the marsh is the same as that of the ditches and stream. 
MOLLUSKS. 
FLUVIATILE SPECIES. 
Physa gyrina, Very abundant. 
Lymnea reflexa. Rare. 
