Geographical Distribution in Birds. 457 
beneath, intervening localities producing specimens having a 
mixture of green and yellow below—either color predominat- 
inas, 
characterized—will, perhaps, render the remarks which follow 
it more lucid: 
Synopsis of the species and their subordinate races of the genus 
Geothlypis. 
Throat yellow, Series I; Throat ashy, Series IT. 
Serrss 1 
A. Black “mask” extending backward beneath the eye, on to the 
auriculars. Bill slender, the culmen nearly straight (as in Opor- 
ornis), 
Bill, from nostril, -30; tarsus, -70; wing, 2°25; tail, 
2°15. Hab. Whole of the United States in summer; in 
* MyIopIOCTES PUSILLUS Var. PUSILLUS. , oe 
eee ee i a a 
815. ird, B. N. Am., in s 
Hab. Eastern Province and Rocky Mts. of N. Am.; eastern middle America 
in winter. 
+ MyYr1opI0cTES PUSILLUS var. PILEOLATA. 
Motacilia pileolata Pallas, Z. R. As., i, 1831, 497. 
‘yiodioctes pusilius var. pileolata Ridgway. . 
¢ HeLMINTHOPHAGA CELATA var. 
Hab Goast, from Radiak , Cape Ben ; 
. Pacific to cas. 
A ‘i iny upon the genus- Geothlypis, by Mr. Salvin, 
very interesting paper upon gen > avila aoe i 
tions are made, and theories suggested, which we may be able to corroborate by a 
few additional facts bearing upon the relationship of the several species of 
Am. Jour. Sct.—Turp Serigs, Vou. IV, No. 24.—Dec., 1872, 
238 
