528 HISTORY OF THE 



work was progressing, I think the nest would have been com- 

 pleted during the day. I do not know that it is the usual cus- 

 tom for the female to confine her labors to the plain and neces- 

 sary work, and the male to the decorative and ornamental parts, 

 but it was so in this case. It may be that the time of laying 

 was near at hand, and that the female felt the pressing necessity 

 for the completion of the interior; for, in such cases, I have seen 

 nests of birds enlarged and completed by the males, while the 

 females were sitting upon their treasures. 



Eggs three to five, usually four; in form, oval. 



Vireo solitarius (Wii-s.). 



BLUE-HEADED VIREO. 

 PLATE XXXI. 



Migratory; rare. Arrive the last of April to first of May; 

 leave on the way southward by the last of September. 



B. 250. R. 141. C. 177. G. 67, 267. U. 629. 



Habitat. Eastern North America; north to Hudson's Bay 

 and Great Slave Lake; south in winter through eastern Mexico 

 to Guatemala; breeds chiefly north of the United States. 



Sp. Char. "Above olive green, including upper tail coverts; the top and 

 sides of head and nape ashy plumbeous; sides of the neck plumbeous olive; 

 broad line from nostril to and around ej^e, involving the whole lower eyelid, 

 white; a loral line involving the edge of the eyelid, and a space beneath the eye, 

 dusky plumbeous; beneath white; the sides yellow, overlaid with olive, this color 

 not extending anterior to the breast; axillars and base of crissum pale sulphur 

 yellow, the long feathers of the latter much paler or nearly white; wings witli 

 two bands and outer edges of innermost secondaries olivaceous white; the quills 

 dark brown, edged externally with olive green, internally with white; tail feath- 

 ers similarly marked, except that the lateral feather is edged externally also 

 with white, the central without internal border. First quill spurious, rather 

 more than one-fifth the second, which is intermediate between the fifth and 

 sixth; third longest. 



" Spring specimens show sometimes a gloss of plumbeous on the back, obscur- 

 ing the olive, the contrast of colors being greater in the autumnal and young 

 birds; sometimes the crissum appears nearly white. The length of the spuri- 

 ous primary varies considerably, from .45 to .75 of an inch. 



"In autumn the colors are similar, but slightly duller and less sharply de- 

 fined, while the back is considerably tinged with ashy." 



