1911] Taylor: Hijhrid Warhler. 175 



midway between that of coronaia and auduhoni. These parts 

 are white, modified on the throat and maiar region by a slight 

 wash of yellow. The shade is not nearly so deep as the yellow 

 of auduhoni. The extent of this slight throat marking is between 

 that in auduhoni and coronaia. In the former the yellow area 

 does not widen posteriorly, while in the latter there is a fiaring 

 of the white area as the upper breast area is approached, and 

 the white area rims up a little on the posterior side of the 

 auricular region. In the supposed hybrid the white-yellow area 

 flares posteriorly as in coronaia, but not to so great an extent. 



If any true intermediate condition exists in the chest region, 

 it is obscured by the fact that no. 6012, representing coronaia, 

 is not quite so much worn as no. 8687, the specimen in question, 

 which is slightly less worn than no. 8682, representing auduhoni. 

 So that, from consideration of plumage, the white areas on the 

 chest feathers of the hybrid would find themselves in a condition 

 between those of the two species. 



The yellow on the sides of the breast is like coronaia in shade, 

 being a trifle lighter than in auduhoni. 



The most obvious and important characters which immedi- 

 ately fix the bird as an intermediate are those of the coloration 

 of the sides of the head and of the chin, throat, and malar region. 

 In matter of tail markings it is nearest coronaia. 



DISCUSSION 



According to Ridgway (1902, p. 548), the breeding range of 

 Dendroica coronaia is North America in general, chiefly east and 

 north of the Rocky Mountains ; from the mountains of western 

 Massachusetts, northeastern New York, northern Michigan, and 

 Manitoba, to the limit of tree growth (Labrador to western 

 Alaska). That of Dendroica auduhoni is given by the same 

 author (loc. cii., p. 553) as being North America, north to British 

 Columbia, east to western border of the Great Plains, breeding 

 southward (in coniferous woods on high mountains) to southern 

 California, etc. Although definite records from middle or north- 

 ern British Columbia or some other of the western provinces of 

 Canada appear to be wanting, it is probable that the breeding 



