1925] Storer: A Synopsis' of the Amphibia of California 215 
a part, just how important a part it is impossible to say with our 
present incomplete knowledge. Before the relative importance of 
these two f actors can be determined we need to know something of the 
temperature cycle and heat quotient of the streams, and we also need 
data on the complete seasonal schedule of Hyla arenicolor in some 
one locality. But that moisture conditions play a very important part 
seems an unavoidable conclusion. 
Hyla reg’illa Baird and Girard. Pacific Tree-toad 
(PL 3, fig. 5; pi. 6, fig. 12; pi. 14, figs. 40-42; pi. 16, fig. 49 [upper left figs.] ; 
text figs. Y, GG) 
Hyla regilla Baird and Girard (1852&, p. 174). Original description, type 
from Sacramento River, California. 
Hyla scapularis Hallowell (1854, p. 96). Type locality, Tejon Pass, Cali- 
fornia. 
Hyla nebulosa Hallowell (1854, pp. 96-97). Type locality, Tejon Pass, 
probably near Fort Tejon, Kern County, California. 
Hyla scapularis var. hypochondriaca Hallowell (1854, p. 97). Type local- 
ity, Tejon Pass, California. 
Hyla cadaverina Cope (1866a, p. 84). Name to replace nebulosa Hallo- 
well, preoccupied. 
Hyla regilla, Cooper (1868, p. 485). General range. 
Hyla regilla, Yarrow and Henshaw (1878, p. 208). Locality records. 
Hyla regilla, Boulenger (1882a, p. 374). General account. 
Hyla regilla, Yarrow (1883, pp. 24, 171, 172). Locality records. 
Hyla curta, Yarrow (1883, pp. 24, 171). Locality record. 
Hyla regilla, Cope (1889, pp. 355-361, text fig. 89). General account. 
Hyla regilla, Stejneger (1893, pp. 222-224). Locality records in eastern 
California and Nevada. 
Hyla curta, Van Denburgh (1895a, pp. 557-558). Application of name. 
Hyla regilla, Test (1898, pp. 477-492, pi. 39). Critical; coloration; meas- 
urements; range. 
Hyla regilla, Van Denburgh (1905, pp. 3, 13, 23). On coastal islands. 
Hyla regilla, Dickerson (1906, pp. 4, 41, 134-138, col. pis. 8, 9, pi. 53 
[figs. 165-169]). General account. 
Hyla regilla, Van Denburgli and Slevin (1914, pp. 132, 135, 137, 144). On 
coastal islands. 
Hyla regilla, Grinnell and Camp (1917, pp. 144-145). Range in California. 
Hyla regilla, Stejneger and Barbour (1917, p. 33; 1923, p. 31). General 
range. 
Hyla regilla, Stephens (1921, p. 60). Range in San Diego County. 
Hyla regilla, Grinnell and Storer (1924, pp. 661-663). Habits in Yosemite 
region. 
Diagnosis . — Smallest native Salientian in California, head-and- 
body length less than 50 millimeters (2 inches) ; all digits with 
expanded terminal discs ; skin smooth, without obvious tubercles ; side 
of head with broad band of dark color through eye, bordered below 
by narrow stripe of white; body coloration highly variable, ranging 
