230 University of California Publications in Zoology [Yol. 27 
orbit; low ridge on upper jaw, beginning below orbit and extending 
posteriorly to a rounded papilla above insertion of foreleg ; tympanic 
membrane separated from orbit, nearly round, diameter about two- 
thirds length of orbit; slight fold of skin extending from posterior 
side of orbit over tympanic membrane to near insertion of foreleg; 
lower jaw narrowly oval, truncate at tip; fore limb slender; exposed 
portion of upper arm shorter than forearm; palm with two parallel 
tubercles; sesamoid tubercles distinct; digits slender, subequal, in 
order of decreasing length, 3, 4, 1, 2 ; sacral hump prominent ; dorso- 
lateral folds slight; hind leg much stouter than foreleg; tibia longer 
than femur; ‘heels’ overlapping when legs are flexed; tarsus about 
one-third length of foot ; foot slender ; two metatarsal tubercles, outer 
one inconspicuous ; sesamoid tubercles large ; toes slender, in order of 
decreasing length, 4, 3, 5, 2, 1 ; web moderate, scalloped to end of first 
phalanx on fourth toe. 
Tongue narrow, scarcely half width of mouth at angles of jaws, 
wedge-shaped, posterior end with two lateral lobes, attached by 
anterior two-thirds to floor of mouth ; internal nares small, well 
behind tip of snout; maxillary teeth large and numerous; vomerine 
teeth large, few in number, in two separate clusters in broad Y-shaped 
arrangement, between and behind internal nares. 
Surfaces of entire animal very smooth everywhere except for slight 
roughening on ventroposterior portions of femurs. 
General coloration (in alcohol) on upper and lateral surfaces dark 
gray, finely patterned with black ; ridge alongside of upper jaw white ; 
tympanic membrane dusky ; spot at origin of foreleg and crossbars on 
fore and hind legs, black ; ventral surfaces dull yellow, mottled with 
dusky. 
Live specimens of aurora from Seattle, Washington, exhibit the 
following coloration. Brown, yellowish or olive ; small spots or specks 
of dark brown or black on head, back and sides ; space behind eye and 
including ear, and line below canthus rostralis, black ; fold of skin 
along upper jaw T under eye to shoulder, yellowish; upper and lower 
lips spotted with dark ; iris golden yellow ; fore limb may be crossed 
by 3 to 5 narrow dark bands; concealed surfaces yellow and black; 
throat and undersurface light, obscurely mottled with dark ; hand and 
foot may be purplish gray; much red in coloration on sides of body, 
on concealed parts of legs and feet, and under arms at insertions 
(adapted from Dickerson, 1906, p. 216). 
Range. — Typical specimens of the present subspecies have been 
taken in California south to Eureka, Humboldt County. Specimens 
from Mendocino City, Mendocino County, are intergrades with dray- 
tonii (Camp, 19175, p. 124). The eastward extent of the range of 
aurora in California is still unknown. In Oregon it has been found 
at Fort Umpqua (Cope, 1889, p. 440), on Wizard Island in Crater 
Lake, Klamath County (Evermann, 1897, p. 230), at Eugene, Lane 
County, and Clear Creek near Oregon City, Clackamas County (Van 
Denburgh, 19125, p. 159), and at Portland (Pope, MS) and Astoria 
