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Oberholser, Description of a Neiv Empidotiax. 



FAuk 

 Ljuly 



whole series, together with others which are apparently intermedi- 

 ates. Whether or not this occurrence of paler birds in the south- 

 western United States shows an inclination of difficilis toward 

 intergradation with cinerithis is not possible certainly to determine 

 from the material at present available, but the greater frequency of 

 such examples in southern California seems at least to indicate 

 that such may be the case. One bird from the Santa Catalina 

 Mts., Pinal County, Arizona (U. S. N. M. No. 1 17235), is very pale 

 throughout, and differs from cineritius chiefly in the quite continu- 

 ously yellow under parts. A specimen from Napa Valley, Cali- 

 fornia (U. S. N. M. No. 12880), is very similar to the preceding, 

 but is browner and slightly darker above, less extensively yellow 

 below, and rather darker across the breast. Whether or not these 

 two specimens are to be called cineritius seems somewhat doubtful. 

 I very much hesitate to record them as such, though they cer- 

 tainly do not represent difficilis^ unless they may be considered 

 abnormally faded summer birds. 



The young of Empidonax difficilis appears to be, as a rule, very 

 brown above and light yellowish or buffy below (not dull white as 

 mentioned by Mr. Ridgway ^), although two immature specimens 

 from Sitka, Alaska, are as bright olive above and as deep yellow 

 below as almost any of the adult examples. 



Measurements of Specimens of Empidonax insidicola. 



^ Manual of North American Birds, 1SS7, 340. 



