and moss covers the ground; but
under the thickest growth of rushes the ground is bare and is
evidently covered by water during a part of the year. On this upland
one small pond surrounded by rushes did not dry up until late in
August. In a few places small blackberry thickets occur in the areas
of rushes and dominate all other plants.

Fifty traps set in this habitat, on August 8, took on the first night
one prairie white-footed mouse and one Pennsylvania vole; the prairie
white-footed mouse was taken just at the edge of the growth of rushes.
Other Pennsylvania voles as well as a lemming-vole, a prairie vole,
and several young ground squirrels were secured on later nights by the
same trap-line. A skunk den was situated in a blackberry thicket in
the midst of the largest patch of rushes.

_Cleared-upland sedge habitat_:

_Peromyscus maniculatus bairdii._ Prairie white-footed mouse. 3.

_Microtus pennsylvanicus pennsylvanicus._ Pennsylvania vole. 1.

_Microtus ochrogaster._ Prairie vole. 9.

_Mus musculus musculus._ House mouse. 1.

_Citellus tridecemlineatus tridecemlineatus._ Thirteen-striped
ground squirrel. Burrows.

Sedges are dominant over a part of the cleared upland, occurring on
the moist gentle slopes which are too well drained for rushes, but not
in any numbers on the drier and higher parts of the upland. With the
sedges there are a few grasses, and the ground is sometimes covered by
a moss, but the sedges are by far the most abundant plant.

Fifty mouse traps set in this habitat took on the first night, August
15, one prairie white-footed mouse and one prairie vole. Other prairie
voles and white-footed mice were taken on later nights, as well as one
Pennsylvania vole and one house mouse. Burrows of the thirteen-striped
ground squirrel were numerous in the sedges.

_Cleared-upland blue-grass habitat_:

_Peromyscus maniculatus bairdii._ Prairie white-footed mouse. 12.

_Mus musculus musculus._ House mouse. 1.

_Citellus tridecemlineatus tridecemlineatus._ Thirteen-striped
ground squirrel. 23.

The most widespread habitat of the cleared upland on the south part of
the preserve is the blue-grass habitat. In this habitat the
blue-grass, _Poa_, is the dominant plant, growing to a height of
usually not over 0.5 meter. With the blue-grass are associated a few
thistles, yarrow, and several other herbs. During the whole period of
my stay in the regi