1925] 
Store r: A Synopsis of the Amphibia of California 
235 
accomplished the result can be maintained for a long period of time. 
The large adult which furnished the basis for the preceding color 
description, while in the laboratory maintained the 'light phase’ just 
described, and this whether exposed to daylight in a glass-walled 
terrarium or in a practically light-tight box. Previously this particu- 
lar individual had been kept in a fish pond in the water of which there 
was an abundance of black peaty material. In that situation the 
frog was quite blackish, that is it was in the 'dark phase.’ Once, in 
the laboratory, when suddenly seized in the hand and taken out of 
its terrarium, the frog ' turned black. ’ The color change was effected 
in a few seconds of time. The change was particularly noticeable on 
the ventral surface, where the red and white areas were largely 
obscured by the spreading of the black pigment. 
Young frogs, just after metamorphosis, are marked with a golden 
iridescence on the dorsolateral folds. 
History. — Rana aurora draytonii was first described by Baird and 
Girard in 1852 from specimens collected by the United States Explor- 
ing Expedition at, or near, San Francisco. The following year it was 
redescribed as Rana Lecontii by the same authors, and Hallowell later 
described frogs of the same species from El Paso Creek, Kern County, 
as Rana nigricans and Rana longipes. The relationships of draytonii 
have been variously interpreted, but it is now known to be a conspicu- 
ous southern form of the aurora stock, which is found along the Pacific 
Coast from southern British Columbia to northern Lower California. 
Range. — Rana aurora draytonii is found chiefly in California. 
Camp (19175, p. 124) draws the line between the subspecies aurora 
and draytonii at Mendocino City, Mendocino County; typical dray- 
tonii extends northward to Gualala, Mendocino County (Camp, loc. 
cit.), to 3 miles west of the summit of Mount Sanhedrin, Mendocino 
County (Mus. Yert. Zool.) ; and to Michigan Bluff, Placer County 
(Grinnell and Camp, 1917, p. 149). Easterly it ranges to Redding, 
Shasta County (specimen in Calif. Acad. Sci.), and into the foothills 
of the Sierra Nevada at Michigan Bluff (as above), at Smith Creek, 
6 miles east of Coulterville, Mariposa County, at Sneding, Merced 
County (Mus. Vert, Zool.), and at El Paso Creek, Kern County 
(Hallowed, 1854, p. 96). In southern California it occurs along the 
base of the San Gabriel and adjacent mountain ranges, as above Alta- 
dena (Storer, MS), at Sierra Madre (Camp, MS; specimens in Mus. 
Vert. Zool.), at Colton (Van Denburgh, 1896, p. 1008), and at River- 
side (Van Denburgh, 1912a, p. 149). In San Diego County it has 
