44 PROCEEDINGS OF THE NATIONAL MUSEUM VOL. 95 
Central America and México these birds are definitely paler in color 
than those on the Atlantic side, the eastern birds, thermophila, marked 
by darker hues both above and below, being fairly uniform from 
Tamaulipas south to Panamd. Those from the Pacific side, while 
always paler, are more variable, so that three forms are at present 
recognized, the palest being extzma in southern Sonora and northern 
Sinaloa. Another race, mexicana, is found in western and south- 
western México, while stirtoni is described from El Salvador. The 
only break on the west side seems to be in Guatemala where Griscom 
has recorded an extensive series from the Pacific slope as the darker- 
colored thermophila. ‘The specimens from Liberia, while slightly 
darker than stirtoni from farther north, are to be identified as that 
race, which in this slightly intermediate type extends down through 
Pigres and San Mateo on the Pacific slope of Costa Rica to David and 
Boquete in northwestern Panamé, according to specimens in the 
U. S. National Museum. The latter localities mark a considerable 
extension of the previously reported range. 
PIAYA CAYANA THERMOPHILA P. L. Sclater 
Piaya thermophila P. L. ScuatrrR, Proc. Zool. Soc. London, 1859, p. 368 (Jalapa, 
Veracruz, México). 
On the southern and southeastern slopes of Volcéin Rincén de la 
Vieja squirrel-cuckoos were fairly common, specimens being taken on 
November 5 and 11. As the sun appeared after rain one morning I 
saw one preening its feathers in the very top of a tall dead tree at the 
edge of a clearing. 
The two listed from the Hacienda Santa Maria, one taken above 
the house at the edge of the Pacific side of the divide, and the other 
two miles or more farther east near Los Cuadros at the head of the 
Atlantic drainage, are both distinctly darker than those obtained at 
Liberia and, while intermediate, belong definitely with thermophila, 
which is darker colored than stirtoni. This section therefore is on the 
line of union between these two races. 
CROTOPHAGA SULCIROSTRIS SULCIROSTRIS Swainson 
Crotophaga sulcirostris Swarnson, Phil. Mag., new ser., vol. 1, 1827, p. 440 
(Temascadltepec, México). 
Near Liberia the groove-billed ani was common through pasture- 
lands and fields where it was seen daily. I shot one for a specimen on 
November 3. At the airports in Santa Cruz and Tempisque as our 
plane came in to a landing I saw little flocks flying hastily to one side. 
The ordinary name for this species in Costa Rica is tico, in Guanacaste 
modified usually to tinco. More rarely I heard them called zopilotillo, 
from their habit of resting with wings spread in the sun lke a little 
zopilote. 
