THE COLINS OR BOB-WHITES. 143 
Adult Male.—Differs chiefly from the male of O. fectoralts 
in having the black band round the base of the throat narrow, 
not extending over the chest, which is dull rufous-chestnut 
like the rest of the under-parts. ‘Total length, 7°8 inches; 
wing, 4°5; tail, 2°5; tarsus, 1°2; middle toe and claw, 1°4. 
Adult Female.—Like the female of O. fectvralis, but slightly 
larger. 
Range.—state of Jalisco, West Mexico. 
V. RIDGWAY’S COLIN. ORTYX RIDGWAYI. 
Colinus ridgwayt, Brewster, Auk, ii. p. 199 (1885); Bendire, 
NevAmer. B. p. 16°(1892). 
Orlyx ridgwayt, Ogilvie-Grant, Cat. B. Brit. Mus. xxii. p. 422 
(1893). 
Adult Male.—Distinguished from all the preceding species by 
having the eyebrow-stripes, chiz, and threat black; and from 
the two following species by having the ches¢ and under-parts 
pale reddish brick-colour. Total length, 8-4 inches; wing, 
4°5; tail, 2°55 tarsus, 1:2; middle toe and claw, 1°35. 
Adult Female.—Closely resembles the females of O. fectoralis 
and O. graysont. Measurements as In the male. 
Range,—Arizona, United States of North America, and 
Sonora in Northern Mexico. 
Habits. Mr. Herbert Brown, who was the first to obtain 
examples of this species, gives the following note:—‘“The habits 
of the Masked Bob-White, so far as we know them, appear to 
resemble very closely those of the Common Quail (O. vir- 
ginianus), Only slightly modified by the conditions of their 
environment. They utter the characteristic call of ‘Bob- 
White’ with bold, full notes, and perch on rocks or bushes 
while calling. They do not appear to be mountain-birds, 
but live on the mesas (table-lands) in the valleys and pos- 
sibly in the foot-hills. > 
