1925] Storer : A Synopsis of the Amphibia of California 
69 
proper part of the body. The flat ‘shovel’ nose makes it readily 
possible for the larva to work its way under the bottom vegetation. 3 
The life-history in relation to the environment . — The data given 
above on distribution and life-history show that Ambystoma calif brni- 
ense is restricted to a limited area in the central portion of California, 
namely, the Sacramento-San Joaquin Valley and the central Coast 
Ranges, and that the seasonal program of the species is arranged to 
accord closely with the peculiar climatic conditions found there. The 
environmental conditions for this species are quite different from those 
obtaining with its close relative, tigrinum, in other portions of the con- 
tinent. It is to be regretted that m> ecologic study of Ambystoma 
tigrinum is available for making a comparison with the life-cycle of 
the California form and for aid in determining the relative importance 
of the various factors in the environment. 
The life-history of Ambystoma calif orniense seems to be closely 
bound up with the annual cycle of moisture conditions in its habitat. 
The mean minimal monthly temperature at no time of year goes below 
the freezing point, therefore temperature can scarcely be said to be a 
limiting factor. But the supply of pond water, necessary for spawn- 
ing purposes, is limited. Garman (1890, p. 190) says that in Illinois 
tigrinum spawned “as soon as the snow disappeared [italics mine] 
which means of course as soon as there was unfrozen water. Here 
calif orniense has little or no experience with freezing temperatures 
save for a few hours on occasional nights. Ponds in central California 
do not remain frozen, but they do dry up because of the low 
atmospheric humidity, and the lack of rain in the summer months. 
Hence a species using these ponds must needs advance its spawning 
to the time when the ponds first become well filled. The autumn rains 
in central California do not ordinarily result in the establishment of 
rain pools. Those first rains wet the ground and later, with the 
advent of additional rain in December and January, ponds are estab- 
lished. Conditions for spawning, so far as Ambystoma calif orniense 
is concerned, become favorable during January or early in February. 
Once the eggs are laid, embryonic development is rapid (thus early 
s A note concerning the method of obtaining these larvae used by the writer 
may be of service to others. In hunting for the animals the collector is best 
equipped when provided with dark-colored rubber boots for wading. Taking up 
a position in the pool and leaning down so that he can see readily into the water 
he should scan the bottom near clumps of green algae or other aquatic plants. 
Sudden movements are to be avoided. Larvae can be captured individually by 
bringing a dip net very slowly under them; then with a quick vertical lift the 
net and contents is brought above the surface of the water. 
