COLAPTES. 403 
(Ferravi-Perez), Chupadero, San José, Concepcion, Chihuahua city, Temosachic, 
all in Chihuahua (W. Lloyd), Ciudad in Durango (A. Forrer), Sierra de Bolafios, 
Sierra de Xeres, Sierra de San Luis Potosi, Sierra de Calvillo, Aguas Calientes, 
Sierra de Nayarit, Sierra Madre de Tepic (W. B. Richardson), Zapotlan (W. 
Lloyd), Guanajuato (Dugés*), Tetelco, Chimalpa, Ixtapalapa, Huipulco, in the 
Valley of Mexico (Ferrari-Perez), Valley of Mexico (Herrera 4 1), 'Temiscaltepec, 
Real del Monte (Bullock), S. Miguel Molino, Texmelucan 9, Totimehuacan 9, in 
Puebla (Ferrari-Perez), Ixtaccihuatl, Popocatepetl (Baker }%), Volcan de Colima 
(W. Lloyd), Omilteme in the Sierra Madre del Sur, Guerrero (Mrs. H. H. Smith), 
Las Vigas (Herrari-Perez), Suapam (Sallé *), Jalapa (de Oca*), Orizaba (Baker 1°), 
Monte Alto (Sumichrast"), Cofre de Perote (Sumichrast’, M. Trujillo), La Parada 
(Boucard *), Totontepec, Tonaguia, Villa Alta (M. Trujillo) *. 
Colaptes mexicanus was described by Swainson from specimens obtained by Bullock 
at Temiscaltepec and Real del Monte in the tablelands of Central Mexico}, and it has 
since proved to be a common species all over this region wherever a suitable country 
exists. Its northern extension reaches far beyond the limits of Mexico, and spreading 
from the base of the Rocky Mountains to the shores of the Pacific stretches to Sitka in 
the far north-west. The birds from this distant region, according to Mr. Ridgway, 
present some slight differences, and are his C. cafer saturatior. Within the limits of 
Mexico some variations also exist, but these cannot well be traced to definite localities ; 
the differences seem all due to some slight shades of colour and of dimensions. Birds 
from our northern frontier States are generally paler and greyer above, whilst those 
from Oaxaca are darker and redder, especially on the head, the birds from the table- 
lands being intermediate. 
A point of considerable interest is associated with this species as regards its relations 
with Colaptes auratus along their common boundary. It was long ago shown by Baird 
that a strip of country between the ranges of the two birds is occupied by a mixed 
form, which he called C. hybridus, believing it to be the result of the interbreeding of 
the two definite species. ‘his interpretation of the facts has been adopted by several 
writers as the most probable explanation of them. Mr. Hargitt, in his ‘ Catalogue,’ 
accepted this view, and from his treatment of the subject Mr. Allen was induced to 
examine a very large number of specimens, with the result that he came practically to 
the same conclusion. But the question cannot be considered settled, for the difficulty 
in accepting the hybridization-theory suggested by Dr. Couesf still remains unex- 
plained. 
Though C. auratus approaches our boundary in Texas, we are not aware that it 
* Mr. Allen’s map gives Tehuantepec as within the breeding-range of C. meaicanus, but without authority. 
We have not traced the bird beyond the uplands of Oaxaca. 
‘+ Birds N.-W. p. 293. 
51* 
