THE MAMMALS OF MOUNT MAZAMA. 
213 
a few places. Large masses of snow remain all summer on the 
north and east slopes, and small streams, turned up on end, dash 
down some of the gulches from the melting snowbanks above. 
Dark coniferous trees, chiefly Hemlocks and Noble Firs, have here 
and there gained a foothold on the steep slopes, and afford pleasing 
contrasts with the sombre gray of the crater. Wizard Island, 
a remarkably perfect cinder cone rising 260 meters (850 ft.) 
above the water on the west side ot the Lake, has a perfect 
crater on its summit, and is fairly well covered with trees — 
Hemlocks, Noble Firs, White Pines and Alpine Firs. A colony of 
Pikas (Ochotona)^ of which I shot one, and a Ground Squirrel — 
probably Spermophilus chrysodierus — seen by Mr. Coville and 
others, inhabit the Island. The Island is separated from the rim on 
the west by a narrow and shallow channel about a quarter of a mile 
in breadth, over which the mammals doubtless crossed on the ice in 
early spring. At the Island I shot two Mallard Ducks, and saw a 
Golden-eye and some Grebes — apparently Podilymhus podiceps. 
A few Tip-ups {Actiiis macularia) and a Water Ouzel [Cinclus mexi- 
canus) were also seen along the rocky shore. Although there are no 
fish in the Lake, amphipod Crustacea and caddice fly larvae abound, 
and millions of black mosquitos, with black, fuzzy antennae, 
swarmed along the shore; being males, these mosquitoes did not 
bite, which was refreshing. 
On the rim of Crater Lake, cliffs and crags alternate with nar- 
row fields of pumice, which latter are buried in snow until late in 
the summer. 
A few mammals live on the inner or lake side of the crater. 
Shrews and Voles inhabit the narrow strips of vegetation bordering 
the springs and streams; Chipmunks enliven the scattered clumps of 
trees; and Pikas, Marmots, and Golden-mantled Ground Squirrels 
make their homes among the heaps of slide rock on the steep slopes. 
The Hemlock Forest. — The whole summit of the mountain 
except the pumice meadows on the rim, is covered by a noble forest 
of Hemlocks and Firs. The dominant tree is the large black-barked 
Alpine Hemlock {Tsuga pattonii) whose trunks sometimes attain 
great size — the largest found by us measuring \ :y^ meters (69 inches) 
