236 DWIGHT 



3. First Winter Plumage acquired by a partial post- 

 ju venal moult in August and September which involves the 

 body plumage, the wing coverts (often the tertiaries) but not the 

 rest of the wings nor the tail. 



Similar to the previous plumage but olive-green replaces the drab and a gray cap is as- 

 sumed. Above, including sides of neck and edgings of wing coverts and auricu- 

 lars olive-green, the pileum slate-gray bordered by two lateral dull black stripes. 

 Superciliaiy line broad, grayish or buffy white. Transocular streak dusky. 

 Below, grayish white faintly washed on the sides with olive-green and on the 

 crissum with primrose-yellow. 



In plumage young and old are practically indistinguishable in 

 the autumn, but the iris of young birds is brown while they 

 remain with us. 



4. First Nuptial Plumage acquired by wear which is 

 scarcely appreciable owing to the soft long-barbed feathers and 

 the habits of the species. Some fading is apparent late in the 

 season. The iris becomes dull red before the birds return in the 

 spring. 



5. Adult Winter Plumage acquired by a complete post- 

 nuptial moult. Practically indistinguishable from first winter 

 except by the red iris but possibly will average richer olive-green 

 above with a grayer pileum, and less washed with buff below. 



6. Adult Nuptial Plumage acquired by wear, as in the 

 young bird. 



Female. — The sexes are alike in plumages and moults, the 

 females in winter dress often browner and duller than the males. 



Vireo philadelphicus (Cass.). Philadelphia Vireo 



1. Natal Down. Pale drab-gray. 



2. Juvenal Plumage acquired by a complete postnatal moult. 



Similar to V. olivaceus and V. gilviis, but darker above and distinctly yellow below. 

 Above, wood-brown, darker and olive tinged on the back and wing coverts. 

 Wings and tail clove-brown with olive-green edgings. Below primrose-yellow, 

 auriculars, orbital ring, and superciliary stripe buff- yellow. Lores and postocular 

 streak dusky. Feet pinkish buff, drying to dusky wood-brown. Bill pale bistre, 

 the under mandible pinkish, drying to a yellowish raw umber-brown. When 

 older the bill dusky and feet slaty. Iris deep hazel-brown. 



3. First Winter Plumage acquired by a partial postju venal 



