24 MICHIGAN SURVEY, 1908. 



out, and, with the addition of Oladonia and some Jumperus nana, forms 

 interrupted patches or streaks. Fig. 33, which farther up the slope fuse 

 and form a solid mat, completely covering the surface of the rock, Figs. 

 33 and 34. The dominant forms are Juniperus procumbens and certain 

 species of Cladonia. This was the only place where /. procumbens was 

 found growing on such an extensive scale, or associated in abundance 

 with Cladonia. This formed a novel and beautiful sight, the light-colored 

 patches of the Eeindeer-lichens in places intermingled with the bright 

 green of the procumbens to form a variegated mat. The beauty of color 

 and pattern is lost in a general view, as in Fig. 34. The White Spruce 

 invades the slope in crevices, just in advance of the solid mat formation, 

 but the soil is so shallow that it may be blown over, as is shown in 

 Fig. 33. Procumbens grows so densely and close to the ground that 

 it greatly favors the formation and retention of the soil, and it appar- 

 ently precedes, on this slope, the Cladonia. In the large crevices within 

 this zone grow patches of White Pine, Balsam, Mountain Alder, Spruce, 

 Birch and Arbor Vitae. The general relations of this slope can easily 

 be seen by a comparison of Figs. 32, 33 and 34, in which is shown the 

 transition from the bare wave washed beach, the flat growing lichens, 

 the pioneers of the mat formation invading the crevices, and the domi- 

 nance of the J. procumbens -Cladonia society with its scattered trees, up 

 the slope into the Balsam-Spruce forest. This same order probably also 

 expresses the succession of plant societies at this place. As previously 

 mentioned, the fauna of the lower beach is quite limited, the greater 

 variety occurring in the pools; but farther up the slope appear various 

 forms which frequent the open. On the scattered part of the Cladonia- 

 procumbens zone occurred the spiders,- Pardosa glacialis and sternalis, 

 the grasshoppers, Circoteitix verrucuUitus, Melanoplus alaskanus and 

 fasciatus. A ground beetle, Pterostichus femoralis was found under 

 Cladonia, and under 'similar conditions were found an abundance of 

 shells, Acanthinula harpa, Strobilops vi/rgo, Vertigo tridentata, Yitrina 

 limpida, binneyana, Euconulus fulvus, Euoonulus chersinus polygyratus, 

 Zonitoides arborea milium,, AgriolimMx campestris, Pyramidula cronk- 

 heitei anthonyi, Helicodicus parallelus, and Cochlicopa lubrica. The 

 number of these shells which have a distinctly boreal range is particular- 

 ly noteworthy, suggesting that such a habitat has some of the character- 

 istics of a "boreal island." 



3. The Cladonia-Juniperus tvana, Soci-ety of the Western Section. 

 Here, as at the eastern section of this slope, the bare lake beach bounds 

 this area shoreward. A general view up this slope is shown in Fig. 

 35. The bare wave-washed lower beach is in the foreground, and the 

 green moss and light colored lichen zone is a broad belt above it, followed 

 in turn by foliaceous lichens, and in the crevices by Aspen. The rock 

 surface is considerably rougher than that of the east beach. In general 

 appearance this beach is much more like that about the camp at Siskowit 

 Bay (V, 3) than the Cladonia-procumbens section, and contains more 

 tof the Low Juniper rather than the Procumbent Juniper. There is 

 also much more exposed rock, and a much more diversified flora. In 

 places the Low Huckleberries are very abundant, while they are not 

 at all conspicuous on the eastern section. To get an idea of the general 

 appearances Figures 34 and 36 should be compared. 



