THE Belding Yellow-throat, Geathlypis beldingi Ridgway, is a rather un- ] common bird in collections. Occurring, as it does, only in the southern portion of the peninsula of Lower California, its development into two subspecies would seem hardly probable, but such is now seen evidently to be the case. During the course of the identification of specimens of Geothlypis in the Biological Survey collection, the writer's attention was called to the very con- spicuous differences between individuals of this species from the Cape San Lu- cas region and those from the central portion of the Lower California peninsula. On further comparison the latter prove to represent a remarkable new subspe- cies, which I take pleasure in dedicating to Mr. Edward A. Goldman, who, with Mr. E. W. Nelson, collected the type series. OeothlYl beldingi goldmani, subsp. nov. CHARS. suBse.--Similar to Geothlypis beldi,gi beldingi, but male with the upper surface much duller, more brownish or grayish (less yellowish) through- out; crown behind the black mask largely or wholly grayish or whitish instead of yellow; yellow of under parts somewhat lighter and confined to throat and breast; lower abdomen white or whitish, instead of usually deep yellow, as in Geothlypis beldingi; sides and flanks paler and more grayish. Femal'e similar to the female of Geothlypis beldingi, but upper parts and sides of head paler, more grayish (less yellowish); yellow of lower parts paler and less extensive, confined to throat and upper breast, the abdomen being dull whitish, slightly or not at all washed with yellow; sides and flanks paler, more grayish. DEscRe?o.--Type, adult male, no. 196026, U.S. Nat. Mus.; San Ignaeio, Lower California, Mexico; October 7, 1905; E. W. Nelson and E. A. Goldman; original number, 11766. Sineiput, lores, ocular region, cheeks, aurieulars, and a narrow line extending diagonally downward and backward to the sides of the throat, black, forming a conspicuous mask; behind this a narrow line of pale grayish mixed with whitish and a little lemon yellow, and on the post- ocular region with lemon chrome; oeeiput and eervix brownish olive, verging toward sepia, with a mixture of fine streaks of lemon yellowish, these mos conspicuous on the oeeiput, and resulting from the largely yellow bases of the feathers, which are incompletely covered by the brownish tips; back and scap- ulars dull eitrine, washed with brownish or grayish; rump similar but lighter and somewhat more grayish; upper tail-coverts of the same color as the back, but paler and of a clearer shade of eitrine; tail dark eitrine, the inner margilts of the teetrices more brownish; wings dark hair brown, the quills and coverts edged with eitrine ;. sides of neck posterior to the grayish band similar in color to the eervix, but less mixed with lemon yellow; anterior lower parts chrome yellow, paling to lemon chrome on the middle of the upper abdomen: lower abdomen dull yellowish white; under tail-coverts basally wax yellowl terminally between wax yellow and old gold; sides and flanks isabella color i thighs between tilleul buff and drab gray; edge of the wing lemon chrome; un- der wing-coverts dull grayish white, washed with lemon chrome. MrAsuurar?s.--Male: Wing, 61.5-65.5 (average, 63.5) mm.; tail, 64-70 (66); exposed eulmen, 12.5-14.3 (13.5); tarsus, 23-25 (24); middle toe without claw, 15-17 (15.7). Female :' Wing, 59-63.5 (average, 60.6) mm.; tail, 60-65.5 (62.1); exposed culmen, 13-13.5 (13.2); tarsus, 21.5-23 (22.2) ß middle toe without claw, 14-15.2 (14.4). ' GEOGRAPItC vSTmBU'ON.--Central Lower California, from San Ignacio to Comondu. lrazs.--This very distinct and unexpected subspecies is most readily distinguished from Geothlypis beldingi beldingi by the whitish crown band, the less yellowish upper parts, and whitish abdomen of the male; and the less yellowish upper surface, and paler, less extensive yel]ow of the lower parts in the female. Birds from San Ignacio, which represent the northern limit of its 'Seven specimens, from San Ignaclo and Comondu, Lower California. =Three specimens, from San Ignacio and Comondu, Lower California. range, are, as would be expected, most extreme in their characters. Two males and two females from Comondu, some distance south of San Ignacio, are inter- mediate between Geothlypis beldingi goldmani and Geothlypis b1/2ldingi beldingq, the females being more like the latter than are the males, which are but slightly different from Geothlypis beldingi goldmani. As a whole the Comondu birds are certainly referable to the northern race. The species has apparently not been found between Comondu and La Paz, Lower California, but Geothlypis beldi,ngi beldingi probably ranges northward at least two-thirds of the way to Comondu. The type of Geothlypis belding is an adult male without date, taken at San Jos del Cabo, in the Cape San Lucas region of Lower California. It is very richly colored above and below, and is similar to most of the series of the southern race examined; hence this name must apply to the Cape San Lucas form. There is some individual variation in Geothlypis beldingi goldmani in the extent of the yellow on the lower parts; also of that on the crown: in two adult males there is no yellow to speak of on the crown behind the black mask; and these specimens, with their pale grayish or whitish crown bands, look very much like some forms of Geothlypis trichas, though their large size, more richly yellowish upper parts, and greater amount of concealed yellow on the occiput and on the whitish post-ocular region separate them at sight from all the forms of Geothlypis trichas. The present new subspecies seems to be chiefly resident, inhabiting a re- stricted area in Lower California, as the only evidenc of its occurrence in the Cape San Lucas region is an apparently immature female (No. 89807, U.S. Nat. 5[us.), taken at San Jos del Cabo by Mr. L. Belding on January 21, 1883. Detailed measurements, in millimeters, of the adult specimens examined in the present connection are given below. 1Geothlypisbeldingi Ridgway, Proc. U.S. Nat. Mus., v, September 11, 1882, p. 344. MEASUREMENTS IN MILLIMEYERS OF SPECIMENS OF Geolhlypis beldingi goldmani COLLECTED BY E. W. NELSON AND E. A. GOLDMAN U.S. Nat. Sex Locality MUS. No. 1960261  San Ignacio, Low- er California 196028  .... 196027 196030 CS .... 196031 CS .... 196032 CS Comondu, Lower California. 196034 CS .... 196029 9 San Ignacio, Low- er California 196033 9 Comondu, Lower California 196035 9 .... Date (1905) Wing Tail Oct. 7 64.0 65.5 " 61.5 64.0 " 63.5 65.0 Oct. 8 65.5 68.0 " 63.5 66.0 Nov. 8 65.0 70.0 Exoosed Tarsus Middle toe culmen without claw 14.0 25.0 16.0 12.5 23.5 15.5 13.5 24.8 15.3 13.3 23.0 15.7 14.3 23.5 15.0 13.0 25.0 17.0 Nov. 9 62.0 64.0 13.5 23.8 16.0 Oct. 7 59.5 60.0 13.2 23.0 15.2 Nov. 8 63.5 65.5 13.0 21.5 14.0 Nov. 9 59.0 61.0 Washington, D. 13.5 22.3 14.0 C., Sept. 8, z9 7.