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University of California Publications in Zoology 
[Vol. 27 
Diagnosis. — As for Bufo boreas halophilus (which see), but ex- 
treme size larger (up to 112.5 millimeters, 4% inches), skin rougher 
between warts, black markings more numerous between warts on back, 
and spread of hind foot between tips of first and fifth toes usually 
more than 36 per cent of body length. 
Comparisons. — See Bufo boreas halophilus. 
History. — This toad was originally described by Baird and Girard 
in 1852 from specimens obtained in Oregon or Washington. The 
following year other material from the same general region was given 
the name Bufo columbiensis and this name was used for many years. 
Recently (Camp, 19175) it was shown that the two names applied to 
one and the same form. Cope in 1866 gave the name Bufo micro- 
scaphus to a form of the present group ; the same author ’s Bufo 
pictus originally described in 1875 (Cope in Coues, 1875), without 
definite locality, was later stated (Cope, 1889, pp. 269, 270) to be a 
young individual of this form. 
Range. — This northern form of the toad of the Pacific Coast 
occupies a much wider extent of territory than its relative in central 
and southern California. Specimens typical of boreas are on record 
in California from Eureka, Humboldt County, Sisson, Siskiyou 
County, and Mono County (Camp, 19175, p. 116). It occurs in the 
Sierra Nevada in the vicinity of Lake Tahoe, 6200 feet (Yarrow and 
Henshaw, 1878, p. 208), on Warner Creek near Mount Lassen at 8000 
feet, and in the Warner Mountains in Modoc County up to 8700 feet 
altitude on Warren Peak (Mus. Yert. Zool.). In Nevada it has been 
taken at Reno (Mus. Yert. Zool.), in the Pine Forest Mountains, 
Humboldt County, up to 8500 feet (Taylor, 1912, pp. 343-344), and 
at Elko, Elko County (Yan Denburgh and Slevin, 1921a., p. 29). In 
Utah it has been recorded at Fort Douglas, Salt Lake County, and 
at various localities in the Wasatch Mountains, Wasatch County, up 
to an altitude of 8728 feet in Big Cottonwood Canon (Yan Denburgh 
and Slevin, 1915, p. 101). In Colorado it was first listed by Yarrow 
(1875, p. 523) under the name Bufo microscaphus from South Park; 
Young (1909, p. 298) recorded it on the east slope of the Rockies 
(the “ Front Range”) on Arapahoe Peak, “28 Kilometers west of 
Boulder, ’ ’ Boulder County. In the western part of Colorado it occurs 
south to Grand Mesa (Ellis and Henderson, 1913, p. 53). It has been 
recorded north in the interior “on the Yellowstone” [in Montana?] 
and at “ Chief 'Mountain Lake” ['= Waterton Lake, Alberta] (Coues 
and Yarrow, 1878, pp. 288-289). In British Columbia it has been 
