20 University of California Publications in Zoology. SVou.9 
Honcomsp VALLEY. 
Holeomb valley, altitude 7200 to 7500 feet, is very similar in 
faunal and floral complexion to Bear valley. It is very arid, 
presenting long stretches of sage, interspersed with considerable 
yellow and Jeffrey pine. There are two small cienagas, called 
Upper and Lower Holcomb. On the ridges the pines are mixed 
with pinon and mountain mahogany. On the north sides of the 
highest eminences on the south rim of the valley are a few firs. 
I saw quite a number of chipmunks (Hutamias speciosus) and 
yellow-headed spermophiles (Callospermophilus bernardinus) im 
the western part of the valley; but birds were few in both species 
and numbers. During my visit, August 26, I saw: rock wren, 
linnet, western bluebird, Audubon warbler, Cassin purple finch, 
Sierra juneco, blue-fronted jay, and Cabanis woodpecker. 
Cactus Pua. 
Cactus Flat is a nearly level pocket on the desert side of the 
mountains at about 6000 feet elevation. To the south rise the 
steep slopes leading up to-the erest of the ridge back of Doble, 
some 1500 feet higher; and to the north it is drained off into the 
Mojave desert, 2000 feet lower, by two divergent canons, Cush- 
enbury and Blackhawk. The ‘‘eactus’’ at Cactus Flat is a spe- 
cies of tree yueea (looking to me quite different from the Yucca 
arborescens of the desert proper, lower down) which grows in 
clumps and solitary trees of large size. This is seen conspicu- 
ously from the road above, as soon as one gets within sight of 
the flat. The flat itself is much hotter than the surrounding 
mountain sides, with the result that we find almost an island of 
desert life (Lower Sonoran) surrounded by Upper Sonoran. The 
only conifers are the pifon and juniper which grow abundantly 
on the slopes. In a few shaded canons good-sized golden oaks 
flourish. The sage (Artemisia tridentata) and serub oak are con- 
spicuous elements of the flora; and several desert species of plants 
are found in close company with species of the Pacifie division 
of their zones. A small ranch, where lives Captain James C. 
Johnston, for many years a resident of Santa Catalina island, 
occupies a small tract on the west side of the flat. The only 
