GEOGRAPHICAL SURVEYS WEST OF 100TH MERIDIAN. 293 
mon ; iu other words , plumbeus appears to be further advanced in the process of differ¬ 
entiation, and hence to be more constant to its type. Too much stress should not, 
however, be laid upon this apparent fact, since the locality of specimens of this race 
appears to be an important factor. Thus, all specimens of the plumbeus vireo that 
we have seen from the neighborhood of Fort Whipple, Arizona, the region whence 
described by Dr. Coues, are extremely typical; but from points farther north, as Forts 
Laramie, Bridger, and thereabouts, nearly all—perhaps all—are to a varying extent in¬ 
termediate. 
Similarly, the eastern slopes of the Sierras and Cascades appear to furnish, in sum¬ 
mer at least, nothing but typical cassini, while from the Calaveras Grove California, and 
other localities on the western side of the mountains, we have both typical and inter¬ 
mediate specimens, both styles breeding. As bearing on the subject, 1 may recall the 
fact that many of the shrikes from the same localities are scarcely distinguishable 
from specimens from Florida ( ludovicianus ). 
To sum up, the solitary vireo, like many other lords, appears to be divisible in three 
distinct races, according as it iuhabits the eastern, the middle, or the Pacific provinces. 
Each has its own restricted summer habitat, where it alone is fouud. In fall the two 
Western mingle, to some extent, during the general dispersion attendant upon the fall 
migration. 
The following figures indicate the size of each of the three forms: 
Solitarim. —Average of 11 specimens: Wing, 2.92; tail, 2.23; bill, .40; tarsus, .71: 
largest individual, 3.0G, 2.35, .38, .72 ; smallest individual, 2.80, 2.15, .40, .73. 
var. plumbeus. —Average of 17 specimens: Wing, 3.14; tail, 2.40; bill, .43; tarsus, 
.74: largest individual, 3.22, 2.45, .43, .77 ; smallest individual, 3.03, 2.25, .43, .74. 
var. Cassini. —Average of 28 specimens: Wing, 2.82; tail, 2.23; bill, .41; tarsus, 
.73 : largest individual, 2.93, 2.27, .42, .67 ; smallest individual, 2.70, 2.01, .43, .73. 
LANIID.E—Shrikes. 
Lanius Liumeus. 
L. ludovicianus excubitoridcs (Sw.). White-rump Shrike. 
Most numerous in summer, when it lives chiefly in the lower foot-hills among the 
sage-brush. Some appear to remain all winter in the latitude of Carson. 
The northern shrike (C. boreaUs) also appears here in fall. 
TANAGRIDJE—Tanagers. 
Pyranga Vieillot. 
P. ludoviciana (Wils.). Louisiana Tanager. 
A summer visitor of the mountains, as high up at least as the Columbia River. 
A nest found June 26, near Susanville, Cal., contai ed three young and two 
eggs, the latter just on the verge of hatching. The nest was a loose structure of root¬ 
lets, similar to the usual style of the P. rubra, and was placed on the extremity of a 
limb of a cottonwood, about fifteen feet from the ground. 
As a rule, our tanagers lay but three eggs, and five must, I think, be a rather un¬ 
usual complement. 
FRINGILLIDvE—Sparrows, Finches. 
Loxia Bri8son. 
L. curvirostra americana, Wils. 
This crossbill becomes numerous in the mountains and on the foot-hills in fall. It 
is presumably a resident in Oregon, although I cannot find any direct evidence to this 
effect. 
Car pod ac us Kaup. 
C. purpureas ealifornicus (Bd.) Californian Purple Finch. 
A single individual of this species was taken at The Dalles on the Columbia in Octo¬ 
ber from a flock of pine finches. This is the first record of its occurrence at any point 
along the eastern slope, its distribution being to the west of the mountains from as far 
north as the Straits of De Fuca (Cooper) to below San Francisco. 
C. cassini Bd. Cassia’s Purple Finch. 
An abundant summer inhabitant in the neighborhood of Carson, and, although, 
perhaps becoming rather less numerous as northern California is reached, the species 
