130 University of California Publications in Zoology [Vol. 27 
the summer dry period, as Ensaiina eschscholtzii and Batrachoseps 
attenuatus are believed to do. That some of the individuals do 
remain on the ground is indicated by the three records given below 
of eggs found at the ground surface in the late summer or early 
autumn months. 
Individuals of Aneides lugubris are sometimes found during the 
daytime in seclusion under rocks on dryish hillsides at long distances 
from trees or leafy debris of any sort. In Claremont Canon near 
Berkeley several individuals were collected in different years under 
rocks on a certain south-facing grass-covered slope where the nearest 
trees were 100 yards or more distant. The soil on this hillside is, in 
late summer, hard and dry. It may be that some of the individuals 
of this species regularly resort to such shelters, venturing forth after 
dark when the temperature has fallen and the relative humidity of the 
atmosphere has in consequence been materially increased. 
Certain peculiarities of structure and habit in Aneides seem to be 
adaptations toward arboreal life. The tail is somewhat prehensile 
(Ritter and Miller). Captive individuals on the edge of a table have 
been seen to use the tail in a precautionary way to insure against fall- 
ing. Likewise captives may sometimes be made to suspend themselves 
by their tails after the manner of an opossum. The tail in the terres- 
trial Batrachoseps and Ensaiina is easily fractured whereas this never 
happens with Aneides. The tail is believed to subserve a different 
function in those species, and in a critical situation such as attack 
by an enemy may be more useful off the animal in distracting the 
attention of the predator from the salamander itself. With Aneides 
the tail seems to.be of prime service to the animal itself and there 
would therefore be little advantage in being able to stuff it. Resting 
specimens of Aneides often curl the tail in a lateral spiral ; no other 
salamander (with the possible exception of Ensatina) is known to do 
this. This habit would seem to indicate a greater voluntary control 
of the tail muscles than is possible in other species, thus facilitating 
prehension. 
In Aneides the tips of the digits are slightly dilated and at least 
in preserved specimens slightly concave beneath, a condition suggest- 
ing the expanded tips of the fingers and toes in the Hylidae, which are 
noted for their climbing ability. Miller (MS) notes that juvenile 
Aneides are better able to climb on the smooth surface of glass than 
are the adults. 
