36 NORTH AMERICAN FAUNA. [xo. 16. 
(2) The Middle Belt or Belt of Shasta Firs (Abirs shastensis). 
Above the forest of ponderosa pines, and therefore not conuected 
with similar forests elsewhere, a belt of Shasta firs averaging 2 or 3 
miles in breadth and 2,000 feet in vertical range completely encircles 
the mountain. It is the distinctive forest of Shasta—a forest of tall 
stately trees, dark, somber, and free from underbrush, though here and 
there beds of the low mountain manzanita (Arctostaphylos nevadensis) 
altord a pleasing relief from the uniform dark brown of the surface 
carpet—usually a shallow layer of fir needles mixed with decayed cones 
and wood. The massive trunks, which on the steep slopes are often 
swollen just above the ground to give greater strength to resist the 
pressure of snow, average from 4 to 6 feet in thickness and some attain 
adiameter of 7 or 8 feet. Above the level of winter snow their northern 
sides are usually covered with the handsome bushy yellow lichen, 
Erernia vulpina, which also clothes many of the branches; and in the 
deuser parts of the forest the trees are draped with pendant masses of 
the long black-beard lichen, Alectoria fremonti. The forest almost 
everywhere consists of large mature trees, and is free from evidences of 
fire; but in one place, between Mud Creek Canyon aud Cold Creek, a 
considerable area, evidently an old burn, is covered with young trees 
averaging perhaps 20 feet in height. 
As arule, the Shasta firs stop abruptly where the white-bark pines 
begin, and trees at their upper normal limit are of full size. But now 
and then on the steep and relatively warm southwesterly slopes of 
the ridges, dwarf Shasta firs occur. The highest point at which such 
were observed was at an altitude of 8,900 feet on the east rim of Mud 
Creek Canyon, where a few stunted trees 3 or 4 fect in height were found 
mixed with white-bark pines. On a similar warm slope west of Squaw 
Creek a scattered line of these trees was noted at an altitude of 8,100 
to 8,300 feet. Here the largest were 20 feet in height. Their bark dif- 
fered materially from that of trees lower down, being pale grayish 
instead of dark brown, and thin, smooth, and full of blisters, instead of 
thick and deeply furrowed. These fir trees were mistaken for another 
species until 1 had the good fortune to find a few bearing cones, which, 
on August 1, were two-thirds or three-fourths grown. To my surprise, 
they had long exserted bracts which, as in the young cones, stood 
straight out horizontally. Very young cones (2 to 34 inches long) always 
appear to consist of bracts alone, the scales being hidden inside. On 
breaking open the cones the tiny scales are seen encircling the axis; 
they are less than half the size of the bracts and occupy the inner half 
of the diameter or section of the cone. 
The normal bark of the Shasta fir resembles that of the alpine hem- 
lock. Itis rather regularly furrowed vertically, and the plates between 
the furrows are cracked horizontally, so that it suggests that of the 
ponderosa pine, though the plates are smaller and less red. Along the 
lower edge of the Shasta tir belt the bark is darker and the cracks 
and furrows are narrower, 
