MICHIGAN ACADEMY OF SCIENCE. 
210 
There is considerable variation from that account in certain respects, 
but these may be omitted from this discussion. To the east of a line 
passing north and south near St. Louis and Ithaca the surface is level, 
the soil consisting of water laid material or lacustrine deposits, with 
but little interruption. West of this line, the surface is marked by low 
moraines extending north and south. The moraines are low on the 
east and increase in elevation toward the west side of the area. These 
moraines vary in the character of their materials, some being covered 
by clay, others consisting entirely of sand and some gravel. The de- 
pressions according to depth and extent contain well drained soils, muck 
and peat deposits and some marl deposits indicating the presence of 
former lakes, and in some of the depressions are still to be found extensive 
swamps, bogs and lakes. Half Moon Lake lying near the northwest 
corner of the area is the largest lake lying within the area. It is 
now about a mile long by one-half mile wide and has suffered great re- 
duction by filling with vegetation. The most interesting part of the 
area from a biological standpoint is a strip along the west side includ- 
ing Half Moon Lake and the moraines to the south. Pine River enters 
the area a few miles southwest of this lake and follows a depression 
southward between the moraines to a point near the southwest corner 
where it turns northeastward across the area. Thus the western part 
has the most varied conditions to be found in the region. 
Aside from the brief mention in the Soil Survey there are no pub- 
lished records referring directly to the plant life of this section. It is 
not possible at this time, nor is it necessary to give a complete list of the 
plants known to be found here. Only those species which have 
particular interest as more southern or northern forms are mentioned, 
and the list does not represent a complete catalog of such forms. It is 
given to illustrate the conditions which a more detailed study would 
more fully reveal. 
Omitting the modern beach and dune formations the habitats and as- 
sociations are comparable to those of the coast. The Mesopliyte Forest 
type prevails over the larger part of the area. This includes level well- 
drained soils, the low moraines and over-wash plains. The fossil beaches 
of early glacial lakes are nearly obliterated, appearing only in certain 
localities on the western border of the lake plains. Through increased 
drainage the Helophyte formations formerly of considerable extent have 
become largely transformed toward Mesopliyte conditions. In the west- 
ern portion where the physiographic conditions are more varied, the 
associations are those usually found from fresh water lakes and reed- 
brush and wooded swamps, to Mesopliyte Forest and sand ridges and 
clay ridges. Any further characterization setting forth the details of 
these as compared with corresponding formations elsewhere is depend- 
ent upon a more detailed study. 
Northern forms that are found on or adjacent to the area and occur 
more rarelv farther southward are: Abies balsamea, Taxus canadensis, 
Picea Mariana, Picea abies, Finns resinosa, Tsuga canadensis (spread- 
ing if permitted) Thuja occ-identalis, Clintonia borealis, Myrica as- 
plenifolium, (rare) Selaginella apus, Epigea repens (occurs westward) 
Gaultheria procumbens, Cornus canadensis, Arethusa bulbosa. Kalinin 
polyfolia, chamaedaphne calyculata, Chiogenes hispidula, Andromeda 
