—43— 
The lists of both Cooper and Kauffman include two additional bryophytes 
which have not been collected in the region covered by the present investigation, 
namely Bryum intermedium (Ludw.) Brid. and Stereodon curvifolius (Hedw.) 
E. G. Britton; while both Conklin and Kauffman list Jungermannia lanceolata 
I ,, and Porella platyphylla (L.) Lindb*. To these should be added, as not elsewhere 
recorded for Michigan, Anacamptodon s plachnoides (Froel.) Brid. and Elodium 
paludosiim (Sull.) Loeske, collected by the writer at Lakeside, Berrien County, 
in 1910. 
Of the 261 species to be noted in the present paper as occurring in the Doug- 
las Lake region, no less than loi appear not to have been previously reported from 
the state. These species will be marked with a star (*). 
For a country of moderately rolling topography with little rugged relief, 
a country of sands and gravels with almost no outcrops of bed rock (except at 
Mackinac Island), a country which has been almost completely lumbered and 
more or less extensively burned over, the comparative richness in species of the 
bryophyte flora in the Douglas Lake region, at first thought, seems almost in- 
credible. But this diversity is at once explained by the surprising variety of 
habitats which this region, superficially so lacking in promise, reveals upon 
closer examination. The principal types of habitat, in so far as these are of 
bryological importance are as follows: 
The Hardwoods. — The magnificent forests of beech, sugar maple and hem- 
lock which, with white pine, formerly covered the uplands throughout this region 
are now represented only by occasional primeval stands and by somewhat more 
frequent second-growth tracts of woodland. 
The Aspens. — The prevailing type of vegetation on uplands today is dry open 
woodland, more or less densely populated by aspen, with a sprinkling of other 
trees. 
The Lake Bluffs. — Steep embankments, usually of gravel and from three or 
four to more than fifty feet high, border the shores of Douglas and Burt Lakes 
in several localities, affording conditions favorable to many bryophytes which 
are found in no other type of habitat. 
Sandy Lake Shores. — Sandy lake shores in general possess little of bry- 
ological interest. Certain species, however, appear to be restricted to the beaches, 
growing at about the level of winter high water mark, but for the most part only 
in places where the ground remains quite moist, even in summer. 
Rocks and Cliffs. — Through most of this region the only rock substrata 
are afforded by the scattered to locally abundant glacial boulders; but Mackinac 
Island abounds in rocks and cliffs, here as elsewhere mainly limestone. 
The Gorge. — One of the most striking physiographic features of the region 
iThe majority of American specimens formerly referred to P. platyphylla, however, are now- 
assigned to P. plalypyhlloidea (Schwein.) Lindb., and only one apparently authentic Michigan 
record for the true P. platyphylla is known, viz., a specimen colbcted at Ann A bor in 1907 by Dr. 
Conklin. 
