164 



White at the base of the tail more extended and brolien, next the dusky 

 portion, with a confused mottling or spotting of grayish and dusliy. 



There is considerable variation in the plumage of this bird at all ages ', 

 but the variations are chiefly in details of coloration, the general style 

 characteristic of the stage being preserved in all cases. In the adult 

 I)lumage, the chief variation is in the proportionate amount of ru- 

 fous on the rump, some specimens having the rump as uniformly 

 rufous as the tibite or lesser wingcoverts, while in others there is only 

 a strong tinge or spotting of this color; the usual condition is to have 

 the two colors mixed in about equal amount. The only conspicuous 

 variation noticeable in the series under examination is in the markings 

 of the tail-feathers, a single specimen, Xo. 9134, having the white of the 

 tip extending on some feathers along the edge and thus connected with 

 the basal white. This condition is so entirely exceptional, however, 

 that we are led to believe that it is purely individual, and outside the 

 normal variations which the species ordinarily presents; In the perfect 

 adult plumage of this form, there are no white or ocliraceous streaks on 

 the throat or cheeks, nor any white other than that described above, ex- 

 cept a faint white sprinkling, seen in some individuals, on the inner 

 webs of the primaries. 



We still separate the northern birds of this species from the southern 

 ones, notwithstanding Mr. Sharpe and other prominent authorities unite 

 them, for the reason that we have yet to see a single South American 

 specimen in which the dusky and rufous of the plumage assumes that 

 uniformity characteristic of the adult specimens from Mexico and ad- 

 joining provinces. The Chilian specimen described above is the black- 

 est example we have seen of the former, while Temminck's plate, cited 

 above (PL Col. 313), represents about the average style. The adult plum- 

 age of the South American bird seems, therefore, to correspond with the 

 immature stage of the northern form, or that stage in which the tail is 

 uniform black on the upper surface, with the characteristic basal and 

 terminal white bands, the black, especially that of the lower surface, much 

 broken by whitish edgings and spottings, and the tibiae merely barred with 

 ferruginous. It is barely possible that we have not seen the most per- 

 fect plumage which the adult of the South American bird attains, but 

 Mr. J. II. Guruey, than whom there is not a more competent authority, 

 in commenting on our statement to this effect in History of North Ameri- 

 can Birds (vol. iii, p. 249), says that so far as he has had an oppor- 

 tunity of examining specimens, our observ^ation is correct. (Cf. Ibis, 

 April, 1875, p. 235.) 



List of specimens in United States National Museum. 



a. UKICIXCTUS. 



Catalogue 



Sex and 



Ko. 



age. 



13907 



? ad. 



13908 



d ad. 



16572 



— JU'^- 



32971 



n " 



32972 



cf jav. 



36G67 



-^JUV. 



48813 



d 



48814 



? 



48815 



? juv. 



49507. 



?.j«v. 



54111 



d juv. 



54935 



— ad. 



Locality. 



Date. 



Chili 





...do 





Bogota 





Chili 





...do 





Amazonia 







June, 1864 



...do 



do . 



...do 



July, 1864 

 May, 1867 



Couchitas, Buenos Avres 



Guayaquil, Ecuador I 



... do 









Donor. 



Lieutenant Gilliss. 



Do. 

 W. Evans. 

 Verreaax. 



Do. 

 N. H. Mus. Ein. 

 Nat. Mus. Chili. 



Do. 



Do. 

 W. H. Hudson. 

 J. E. Keeves. 

 Dr. Destruge. 



OtJie)' specimens examined.- 

 4 ; total, 26. 



-In mus. Pliilad. Acad., 9; Am. Mus., N. Y., I; Bo.ston Sec. 



