158 DWIGHT 



chief differential character is however the presence of a few black 

 feathers, usually yellow tipped, irregularly scattered on the chin 

 and breast. A specimen from Jamaica, West Indies, September 

 25th (Amer. Mus. Nat. Hist. No. 42134), is an extreme example 

 with numerous black and mottled feathers, the black distributed 

 irregularly, varying from shaft streaks to asymmetrical blotches. 

 As these feathers all show wear similar to those adjacent, there 

 can be no doubt that all of them grow at the postnuptial moult. 

 I have seen a few, autumnal adults, but they are excessively rare 

 in collections and their rarity is largely responsible for the ignor- 

 ance that has prevailed regarding the normal plumages of the 

 Bobolink which conform to the ordinary laws of moult and are 

 in no respect unique. 



6. Adult Nuptial Plumage acquired by a complete pre- 

 nuptial moult in midwinter. Differs inappreciably from first 

 nuptial dress, but it is probable that (as in other species) the 

 yellow edgings diminish with age. The classic Corumba bird 

 mentioned above and discussed at p. 122 of the present article, 

 was first described by Chapman '90 and later figured in (Auk, 

 X, 1893, pp. 309-311, pi. vii.). It is completing a perfectly 

 normal prenuptial moult, and seems to be an adult, because a 

 few old black feathers of the adult winter plumage are present and 

 the whiteness of the abdomen indicates the fading of feathers that 

 are nearly w^hite over this area in adults in the autumn. At all 

 events the worn and faded feathers that remain on this specimen 

 are exactly where the last traces of moult are found in a normal 

 moult not only of this species but of all Passerine species examined 

 and there is not the slightest evidence of the supposed color 

 change to black without moult that has been alleged. 



Female. — The plumages and probably the moults correspond 

 to those of the male. In ju venal and first winter plumage the 

 sexes are indistinguishable. The first nuptial is no doubt ac- 

 quired partially at least by a prenuptial moult, judging by wear 

 and by a caged female examined when moulting the remiges, the 

 buff being paler than in first winter dress. The adult winter 

 plumage is practically indistinguishable from the first winter. 

 The adult nuptial is similar to the first nuptial. A bird seen by 



