82 University of California Publications in Zoology [Vgl. 27 
four masses, advanced in development, on April 28. These were for- 
warded at once to Berkeley and arrived in good condition for study 
on the day following. In 1924 three masses, with early embryos, were 
found on or just prior to February 20. These were at once preserved 
in formalin and subsequently shipped to the writer. 
In the 1923 material the embryos in one egg mass had not begun 
to hatch, in a second some still remained in their capsules, while prac- 
tically all were out in the remaining two masses when received at 
Berkeley. Some had evidently emerged while en route. The embryos 
in the first mentioned mass began hatching on April 29. The embryos 
in the 1924 material were only about 5 millimeters in length when 
preserved. Egg deposition in the latter case had in all probability 
occurred prior to the middle of February. The two seasons of 1923 
and 1924 were so different in character as to make it impossible to 
say whether the two lots of material represent the two ends of the 
normal seasonal program of Dicamptodon. I am inclined to believe 
that spawning occurs during March of normal years and that the 1924 
material was deposited fully a month earlier than usual. 
The following table gives the measurements of these egg masses. 
Date collected 
Weight in 
grams 
Volume in 
cubic 
centimeters 
Approximate outside 
dimensions in millimeters 
April 28, 1923 
304 
290 
110 X 70 X 70 
April 28, 1923 
286 
280 
110 x 70 x 70 
April 28, 1923 
214 
220 
70 x 75 x 65 
April 28, 1923 
184 
180 
80 x 70 x 60 
About Feb. 20, 1924 
230 
80 x 60 x 60 
About Feb. 20, 1924 
240 
80 x 65 x 55 
About Feb. 20, 1924 
155 
70 x 70 x 45 
The individual capsules in which the embryos develop are 6.5 to 
7.0 millimeters in diameter in the younger (1924) material and about 
10 millimeters in the 1923 masses. As with egg masses of other species, 
the size of the mass increases as development proceeds. More space 
is thus afforded for the embryos as they grow in length. 
There seems to be only one layer of jelly surrounding each egg, and 
this, in masses advanced in development, is about 2.5 millimeters thick 
around each capsule. A complete mass is evidently composed of sep- 
arate egg capsules, which, upon being laid in groups, absorb water and 
adhere to each other so closely as to defy subsequent separation (pi. 8, 
fig. 19 ; text fig. V). 
