72 CALIFORNIA ACADEMY OF SCIENCES [Proc. 4th Ser. 



plumage with dusky mesial stripes on many of the feathers of 

 the upper parts. These two specimens also show pink feath- 

 ers replacing the worn faded feathers of the head and neck, 

 and apparently working from the head downward. The 

 bases of the new feathers appearing in the head and neck are 

 gray as in the ju venal plumage, and not white as in fully 

 adult specimens. No. 2232, October 5, and No. 2238, Feb- 

 ruary 26, both from Charles Island, seem to show this fourth 

 plumage somewhat farther advanced. Scarlet upper wing- 

 coverts, occasionally with dark shafts, are appearing, and pink 

 feathers are replacing the worn, faded feathers of the under 

 parts. Pinkish-white feathers are also taking the places of 

 the long bicolored scapulars, and new upper tail-coverts are 

 appearing. No. 2238 shows the old and new upper wing- 

 coverts in alternating rows. No. 2208, south Albemarle, May 

 1, is still farther along, yet shows outward signs of imma- 

 turity in the wing-coverts, scapulars, tertials, upper tail-coverts, 

 tail, and the dark color of the naked parts. Many old worn 

 feathers of the third plumage are still to be found in the neck, 

 hidden beneath the new feathers, which, as mentioned above, 

 have dark bases. To sum up, the five immature birds just dis- 

 cussed are all in moult, apparently from the juvenal plumage 

 to a plumage superficially adult, but distinguished from the 

 full adult plumage by its paleness, by the dusky bases of the 

 feathers of the head and neck, by the dark shafts of the axil- 

 laries, and by the more or less frequent occurrence of dorsal 

 feathers with a dark mesial stripe or at least a shaft partially 

 dusky subterminally. For the sake of convenience this 

 plumage will be spoken of as the fourth plumage. 



The following table gives the measurements in millimeters 

 of all the young and immature specimens, referred to in the 

 foregoing account, arranged according to age, as apparently 

 indicated by the plumage. 



