12 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
On November 6 I shot an adult female near the ground in heavy 
forest at Los Cuadros on the Hacienda Santa Maria. 
CHAMAETHLYPIS POLIOCEPHALA ICTEROTIS (Ridgway) 
Geothlypis caninucha icterotis Ripaway, Proc. U. S. Nat. Mus., vol. 11, Sept. 20, 
1889, p. 539 (Costa Rica). 
Near Liberia I shot two of these ground-chats on October 26 and 
November 18 in brush-grown fields where there was much high grass. 
At the Hacienda Santa Maria I found them in grass and weeds 
bordering thickets on the rolling slopes below the house. Specimens 
were taken here on November 7 and 15. The birds were completing 
the molt at this time and were secretive and hard to find. 
Review of available material leaves no doubt in my mind that 
icterotis is a valid form and one to be recognized. In breeding dress 
it is distinctly different from C. p. caninucha in being duller green 
above, and paler yellow with the yellow more extensive. The 
flanks are lighter brown. In fresh fall plumage it is definitely browner 
above. It is similar to C. p. palpebralis in extent of yellow below but 
has the flanks deeper brown and the dorsal surface greener. 
From available material it appears that the following races of this 
species should be recognized: | 
Chamaethlypis poliocephala ralphi (Ridgway): 
Geothlypis poliocephala ralphi Ripaway, Proc. U. 8S. Nat. Mus., vol. 16, Feb. 5, 
1894, p. 692 (Brownsville, Tex.). 
The palest of all the races; compared with C. p. poliocephala sides 
and flanks lighter brown, yellow of breast paler, and abdomen much 
whiter. 
Lower Rio Grande Valley in Texas south into northeastern México. 
The present extent of the range of this species in México is uncertain. 
A good series at hand from Brownsville leaves no question as to its 
validity as a distinct form, though currently it has been placed in 
the synonymy of poliocephala. 
Chamaethlypis poliocephala poliocephala (Baird): 
Geothlypis poliocephala Batrp, Review of American birds, Apr. 1865, pp. 220, 226 
(Mazatlan, Sinaloa). 
Compared with ralphi breast and foreneck deeper yellow, the color 
more extensive; flanks and sides darker brown. 
Northern and central México, from Sinaloa to Morelos and Micho- 
acan. 
Brodkorb has separated birds from Morelos and Michoacin under 
the name pontilis 7! on the basis of supposed larger size. The few 
21 Chamaethlypis poliocephala pontilis Brodkorb, Journ. Washington Acad. Sci., vol. 33, Feb. 15, 1943, 
p. 33 (Puente de Ixtla, Morelos). 
