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University of California Publications in Zoology [Vol. 27 
go in the direction of terrestrial existence, short of the development 
of a dermal armor to check loss of moisture. The three genera of 
Plethodont salamanders in central California seem to represent three 
distinct ecologic types, one ( Batrachoseps ) occupying small holes in 
the ground such as made by earthworms and other invertebrates, a 
second ( Ensatina ) living in terrestrial burrows of larger animals 
(Mammalia), and a third type ( Aneides ) dwelling at or above the 
ground surface in rotted logs or stumps, in wood-rat nests, and in 
rotted-out cavities in live oaks. Ecologic competition in the matter 
of daytime refuges and breeding places would seem to be avoided, 
and there seems to be some segregation with respect to food habits as 
well. 
It seems not without significance that the range of Aneides l. 
lugubris, so far as known, does not extend far if at all beyond that of 
the California live oaks ( Quercus agrifolia and Q. wislizenii) . The 
arboreal shelter offered by the oaks at Berkeley (before they were 
cemented) would probably be duplicated in the trees of this group 
at other places within the State. The other local species of oaks may 
or may not afford conditions suitable for this salamander. The golden 
oak ( Quercus chrysoiepis) occupies a somewhat wider range than the 
species previously mentioned and might be serviceable to Aneides. 
Suitable cavities may occur, for example, in the valley oak ( Q . lobata) 
of the Sacramento-San Joaquin basin and other interior valleys, but 
Aneides could scarcely be thought to live, or at least to spread, as a 
species, under present climatic conditions in the Great Valley where 
there are frequent winter floods and prolonged summer dry periods ; 
the deciduous blue oak ( Q . douglasii) of the foothills seldom affords 
cavities of a size suited to the requirements of a salamander ; the 
black oak ( Q . kelloggii ) has smoother bark and is often of tall habit, 
involving greater danger of falling to an animal of imperfect scansorial 
development. Furthermore, the cavities in this species of oak are 
made use of by arboreal squirrels ( Sciurus griseus and Glaucomys 
sabrinus) which fact might preclude their use by a salamander. If 
the observations by Miller (MS) indicating use of fungus as food, 
particularly during the summer season, represent a normal habit of 
the species, the possible restriction of this fungus to the live oaks 
might be a factor in controlling distribution. 
Several structural specializations of Aneides point toward suc- 
cess in arboreal life. These are the prehensile character of the tail, 
short digits with expanded tips, development of blood sinuses in the 
