620 



PATAGONIAN EXPEDITIONS I ZOOLOGY. 



minal bar deep ashy grey, and the region in front of the sub-terminal band 

 crossed by eight or more narrow obscure blackish bars that are almost 

 lines, as in the adult. The rusty color on the shoulders more pronounced 

 than in the young male. 



Downy young. Upper part of the head dark sooty brown, nearly black 

 about the eyes, shading into lighter smoky brown on the neck and back, 

 this becoming lighter toward the region of the tail ; on the lower neck and 



FIG. 310. 



*&^ u^a^; 



Tachytriorchis albicaudatus. Female of the year. From a bird in the American 

 Museum. One-fourth natural size. 



breast the sooty brown fades into buff and this into nearly white on the 

 abdomen. There is a male, apparently perfectly adult, in the collection of 

 the American Museum of Natural History, No. 34, 710, which is figured on 

 p. 622. (Fig. 312.) This bird presents what appears to be a dimorphic 

 phase of plumage. It is dusky or blackish throughout except on the rump, 

 the upper tail-coverts and the region about the vent and lower tail-coverts, 

 all of which are white and in markings much as in the ordinary adult male ; 

 the tail is like that of the ordinary male bird, white with a sub-terminal 

 broad black band, a terminal white bar, and the region of pure white in 

 front of the sub-terminal band crossed by narrow lines or bars of 

 dusky. 



