b22 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



of tliroat and abdomen; mandible usually much darker than in M. 

 virens, very rarely whitish. Young with darker color of under parts 

 more extensive, darker and browner in hue, the under parts more or 

 less suffused with pale brownish buffy." 



Adult male.— hength (skins), 126-154 (143); wing, 84.5-93.5 (87.4); 

 tail, 59.5-69.5 (66); exposed culmen, 12.5-14 (12.9); tarsus, 12.5-14 

 (13.4); middle toe, 7.5-9 (8.2).'' 



Adult female.— Length, (skins), 131-155 (138); wmg, 79-92 (82.8); 

 tail, 57.5-71.5 (62); exposed culmen, 11.5-14 (12.7); tarsus, 12.5-14 

 (13); middle toe, 7-8.5 (7.9).^^ 



Western North America ; north to Alaska and Northwest Territory 

 (Skagway; Haines; Windy Island; Lake Tagish; Little Salmon 



a Although convinced, from intimate personal acquaintance of both in life, that this 

 form and M. virens are specifically distinct I am at present iinal)le to give a better diag- 

 nosis. The differences are more easily seen than described ; but nevertheless it is often 

 difficult to identify specimens as one or the other without doubt. It is not at all 

 unlikely that this difficulty may be in part owing to the inclusion imder the name 

 richardsonii of what may be in reality two or three distinct forms; otherwise it is hard 

 to account for the unusual variations of coloration noticeable in a large series. While 

 appreciating and verifying the characters ascribed by Doctor Bishop to his supposed 

 northwestern form (Contopus richardsonii satiiratus), as compared with a large number 

 of other specimens, I am, unfortunately, unable to verify any geographic correlation 

 in the matter, these darker birds occurring almost everywhere outside the limits of the 

 supposed subspecies. At the same time there occur in Arizona and adjacent territory 

 many specimens which are decidedly paler and more uniform in color than are found 

 elsewhere, but here also these pale birds inhabit the same areas (possibly, however, not 

 exactly the same localities) as birds of the ordinary style. This pale form, if formally 

 recognized, would bear the name Myiochanes richardsonii veliti (Coues), but I do not 

 at present, at least, venture to recognize such a subspecies. The group is an exceed- 

 ingly diflicult one, which will require not only a very large amount of material, but 

 also much time and patience for its satisfactory elucidation. 



b Thirty-six specimens. 



c Thirty-one specimens. 



Locality. 



MALES. 



Five adult males from Colorado and Montana 



Ten adult males from Arizona (9) and Chihuahua (1) 



Six adult males from San Diego Co., California 



Nine adult males from central California to Oregon 



Si.x adult males from Alaska and Northwest Territory 



FEMALES. 



Five adult females from Utah, Colorado, and Montana 



Nine adult females from Arizona (6), New Mexico (1)^ and 



Chihuahua (2) 



Four adult females from San Diego Co., California 



Ten adult females from central California to Washington.. 

 One adult female from Alaska 



Wing. 



89.2 

 86.8 



87.3 

 8(i.2 



82.3 

 82 

 81.9 

 81 



65.9 

 63.9 

 64.3 

 63.8 

 63.3 



61.8 

 60.4 

 60.9 

 61 



Ex- 

 posed 

 culmen. 



12.9 

 13.7 

 13.3 

 13.3 

 12.8 



12.7 

 12.8 

 12.9 



Tarsus 



13.8 



13 



13.1 



13.4 



13.9 



13.2 



13.1 

 13 



12.9 

 13 



Middle 

 toe. 



8.3 

 8.1 

 8.1 



8.2 

 8.2 



