310 BULLEnN 121, UNITED STATES NATIONAL MUSEUM. 



The black feathers of the interscapular region appear imme- 

 diately after the down on this portion has pushed through the skin, 

 and " before there is any evidence of the remiges and rectrices they 

 cover the back like a mantle * * *. Not only are the wing feath- 

 ers late in appearing, but the secondaries precede the primaries, the 

 former averaging 2 inches in length, with the greater and median 

 coverts showing, when the latter are just observable." This seems 

 remarkable and contrary to the rule with birds of great wing and 

 tail development. 



Plvmvages. — The sequence of molts aijd plumages in this species 

 are puzzling and their study is complicated by the prolonged and 

 variable breeding season, which makes it difficult to estimate the 

 age even approximately. In the juvenal or fii-st-year plumage, the 

 head, neck and under parts are wMte, in both sexes, with dusky 

 flanks and sometimes more or less brownish mottling on the head and 

 neck; the lesser wing coverts are brownish and the upper parts are 

 dull, dark brown, without any luster ; the tail is comparatively short 

 and the lateral rectrices are not much longer than the others. I 

 have seen birds in this plumage in January, May, July, and Oc- 

 tober, from which I infer that it is worn for one year, but the date 

 of the molt into the next plumage is very variable, depending, I sup- 

 pose, on the date at which the young bird was hatched. An interest- 

 ing phase of this first year plumage of the male which I have seen 

 in nearly every Pacific specimen that I have examined and have 

 never found in any Atlantic specimen, is the rich " cinnamon " suf- 

 fusion which -partially or largely covers the breast, neck, and head. 

 Mr. Edward W. Gifford (1913) says of the birds collected for the 

 California Academy of Sciences, in the Galapagos Islands : " Birds 

 in Juvenal plumage, have the entire head and neck a rich cinnamon- 

 rufous. No exception to this is found in the academy series." I 

 have also seen cinnamon-headed birds from Lower California, 

 Necker Island, Madagascar, Laysan Island, and the Phillipines. 

 That this character should hold constant in the large series of birds 

 that I have examined from both oceans is confirming evidence that 

 they are distinct species. This plumage is also probably worn 

 throughout the first year, as I have seen it in January, March, May, 

 September, and October birds. 



After the first year the sexes become dissimilar in plumage. The 

 male becomes much darker on the upper parts, almost black, but still 

 lacks the glossy tints of the adult ; the lateral rectrices become more 

 elongated ; and the head, neck, and under parts become mottled with 

 dusky and white. The female acquires more dusky on the head and 

 neck, as well as on the belly, but the breast and sides still remain 

 white. During the third year, probably at the second postnuptial 



