246 Todd, Bahaman Species of Geothlypis. [£$ 



less resistant. While it is quite true that adults and young of 

 Geothlypis tiichas are indistinguishable in nuptial plumage by color 

 characters, it is unsafe to assume that the same condition holds in 

 the Bahama species, inasmuch as it is now known that allied 

 species may moult quite differently. As previously noted, there 

 seems to be no prenuptial moult in the Bahaman species, while a 

 specimen (No. 14988, Bangs Collection, Little Abaco, July 11, 1904) 

 in postjuvenal moult is assuming the black "mask," also the dull- 

 colored plumage of the posterior under parts supposed to be char- 

 acteristic (in this case) of G. incompta. Moreover, an "adult" 

 specimen of G. rostrata (No. 30G38, Collection Carnegie Museum, 

 Blue Hills, New Providence, January 6, 1909), seems to have an 

 elastic soft spot in the skull, indicating immaturity. Unless speci- 

 mens showing a moult from the Juvenal plumage directly into a 

 bird of the bright-colored style are forthcoming, therefore, we are 

 fully justified, I think, in accepting the explanation advanced by 

 Mr. Bonhote, which covers all the facts in the case except the 

 matter of the alleged difference in song. Regarding this point 

 further field observations are desirable, but it is very likely, as 

 Mr. Bonhote suggests, that age might be responsible for this also. 

 However, it is significant that Mr. Riley states that a " specimen 

 of tanneri [the Abaco representative of maynardi] taken was sing- 

 ing a song somewhat resembling the well-known notes of G. tiichas, 

 but probably with more force." 



As might be expected, the immature birds are less numerous 

 than the adults, and the small series of Eleuthera skins which 1 

 have examined does not happen to contain any. 



Although the three forms which appear worthy of recognition 

 are not known actually to intergrade, it seems best to regard them 

 as insular forms of one specific type, Geothlypis rostrata Bryant. 

 The distinctive characters of the adult males are as follows: 



Crown decidedly grayish; superciliaries faintly yellow-tinged; back dull 

 olive green; flanks greenish yellow. (New Providence, Andros.) 



Geothlypis rostrata rostrata. 



Crown more greenish (only superficially grayish) ; superciliaries decidedly 



yellow in front; back brownish olive green; flanks brownish olive 



yellow. (Abaco, Great Bahama, etc.) Geothlypis rostrata tanneri. 



Crown decidedly yellowish green; superciliaries bright yellow; back 



bright olive green; flanks greenish yellow. (Eleuthera.) 



Geothlypis rostrata coryi. 



