14 U.S. NATIONAL MUSEUM BULLETIN 2 65 



If this species had two distinct, seasonal, adult plumages in the 

 male, this would constitute a real biological disparity, for no such 

 situation is known to exist elsewhere in the genus. Examination of 

 a good series of adult males (41 specimens) in the British Museum 

 partly, but not very convincingly, bears out Ticehurst's findings. 

 It suggests that some of the adult males, presumably, but not cer- 

 tainly, birds in the first adult plumage, tend to be more coppery- 

 bronze and less bright green on the upperparts than do other (older?) 

 birds and that these same individuals tend to have the ventral bars 

 more bronze and less green as well. The appearance of a few white 

 bars on the throat and breast of adult males seems to be almost 

 haphazard (about 20 percent of the specimens showed one to three 

 such marks and these are not all examples taken in any one season) , 

 Three examples, however, do show what Ticehurst described. Two 

 were collected at Dibrughur in August 1879 by J. R. Cripps, and one 

 at Bangkok, on January 25, 1923 by Sir W. J. F. Williamson. In 

 them the feathers of the forehead and the foreparts of crown, chin, 

 and throat are dark, bright green, conspicuously barred wdth white, 

 while the posterior parts of the crown, occiput, back, and rump show 

 a mixture of bright-green feathers mth some that are darker and 

 more bluish, but hardly coppery bronze as Ticehurst MTote. This is 

 true for the two Dibrughur specimens, but not so for the one collected 

 at Bangkok. Inasmuch as this barred forehead, chin, and throat condi- 

 tion is shown by only 3 out of 41 fully adult males, it is not certain 

 that they really represent a distinct nonbreeding, adult-male plumage. 

 Since no such seasonal plumage is known for any of the other glossy 

 cuckoos, it would seem safer (but not necessarily more accurate) to 

 consider these birds as examples of partly retarded plumage char- 

 acters, retaining the bar-producing tendencies of the immature stage 

 beyond their usual duration. Deignan (1945, pp. 164-165) apparently 

 considered Ticehurst's nonbreeding plumage stage uncertain, since he 

 referred to one of his specimens as "completing a molt from the 

 Juvenal plumage to one like that described by Ticehurst ... as the 

 dress of 'the adult male in winter.' " 



Further evidence of the close relationship between xanthorhynchus 

 and maculatus is afforded by four examples of males of the former in 

 early or later stages of molt from the immature to the adult dark- 

 purple plumage. In these four specimens, taken in the following 

 locahties: two from Lower Pegu, December 20 and January 11, 

 1878; one from Bangkok, March 5, 1918; and one from Karen-nee, 

 March 15, 1874. The dark abdominal bars on these specimens are 

 bronze-green as in maculatus, although the new feathers of the throat 

 and upperparts are the deep purple normal to xanthorhynchus. Fur- 



