CHAEADEIUS. 



143 



KEY TO THE SPECIES. 



The following key is imperfect, because it does not enable the student to discriminate 

 between the young in first plumage of G. mongolicus and C. bicinctus, neither of which 

 show any trace of one or more dark bands across the breast. 



Lores pure white 



Terminal vault of bill -5 (adult) to -4 

 (juv.) inch long. 



Breast of adult f Black and chestnut 

 crossed hj-( 

 two bands: I Both black . . 



asiaticus 



montanus . 

 ' wilsoni . . 



geoffroyi. 



obscurus • . 

 . frontalis • • 



mongolicus. 



bicinctus. 

 falklandicus 



>- Legs and feet pale. 



Middle toe and claw 1^ 

 inches long. 



Bill bent sideways. 



Upper tail-coverts nearly 

 black. 



Young in first plumage of C. mongolicus and C. bicinctus are very difficult to distin- 

 guish, and it is not absolutely certain that they can in all cases be distinguished. The bill 

 of C. mongolicus is generally, but not always in young birds, stouter than that of C. bicinctus. 

 The length of tail is a better character, though it also is not always reliable in the case of 

 young birds ; but if it exceed two inches the bird may be referred to C. bicinctus, and if it 

 fall short of that dimension it probably belongs to a young bird of C. mongolicus. In both 

 species adults have longer tails. 



