1925] 
Storer: A Synopsis of the Amphibia of California 
203 
takes as proof of common ancestry. The distinction between wood- 
housii and co gnat us has been indicated in the present paper in the 
paragraphs on ‘ ‘ Comparisons. ’ ’ 
Ruthven (1907, p. 508) says that at Alamogordo, Otero County, 
New Mexico, all the specimens of woodhousii which he obtained 
. . . were taken in the evening along irrigating ditches in the Mesquite association 
on the plains. As in the case of B. punctatus, the natural habitat of var. wood- 
housii is probably the canons in the mountains, where moisture is more abundant, 
and it can be considered to have extended its range out onto the plain with the 
advent of irrigating ditches. . . . During the intense heat of the day these toads 
were not seen, but about dusk they came out in numbers along the shallow ditches, 
especially near street lamps. 
Beetles there make up the bulk of the food. 
At Bellevue, Washington County, Utah, altitude 4000 feet, this 
species was found breeding “ during May [1917] in irrigation ditches 
and springs” (Engelhardt, 1918, p. 78). 
Pack (1922, pp. 46-47) has described the response of a toad popu- 
lation comprised of Bufo woodhousii to an outbreak of sugar-beet 
webworm in Cache, Utah, during August, 1921. 
Most of the toads were of this year’s brood, ranging in length from one and 
a fourth to one and a half inches. I wmild estimate that in one field of about 
one square acre there were no fewer than one hundred toads. 
An examination of the stomach contents of a number of toads disclosed the 
fact that they were feeding exclusively upon the webworms and that every one 
was gorged to the limit. These small toads contained from 24 to 40 worms each, 
the limiting factor in quantity being the size of the stomach. A number of repre- 
sentative toads were weighed, and the stomach contents of each were then removed 
and weighed. It was found that the contained food represented 16 per cent of 
the total weight of the toad. . . . 
From this case it would appear that the toad exhibits the same valuable 
adaptibility in the presence of an insect outbreak as has been observed in birds. 
Not only is there a concentration in numbers of toads in the infested area, but 
the dominating insect, especially if present in great numbers, is eaten almost to 
the exclusion of the insects and other invertebrates normally constituting its food. 
Hyla arenicolor Cope. Canon Tree-toad 
(PI. 2, fig. 4; pi. 13, figs. 37-39; text figs. Z, LL) 
Hyla affinis Baird (1854, p. 61). Original description, type from northern 
Sonora, Mexico. 
Hyla arenicolor Cope (1866a, p. 84). Name to replace affinis, preoccupied. 
Hyla arenicolor, Yarrow (1883, pp. 24, 175). Range. 
Hyla arenicolor, Cope (1889, pp. 369-370, text fig. 93). General account. 
Hyla arenicolor, Dickerson (1906, pp. 122-123, pi. 48). General account. 
Hyla arenicolor, Richardson (1912, pp. 605-611, 1 text fig.). Range in 
California and elsewhere. 
