178 GENERA AND SPECIES. 



and washed with green on the upper tail-coverts; 

 wings greyish brown, with purple reflexions ; 

 throat rich lustrous grass green ; breast and 

 abdomen rich deep bluish black; flanks rusty 

 brown ; tail green, with bronze reflexions ; bill 

 black ; feet olive black. 



Total length, 5 inches'; bill, 1 ; tail, 2|. 



It is most probable that many new species 

 will be hereafter added to this genus, which is as 

 well defined in form and general features as it is 

 in its habits ; not that there are no other I 

 Humming-birds, to which the term Nivicolce is 

 applicable : but in this genus, every species is a 

 tenant of the highest habitable range of th< 

 snow-clad mountains, and builds its nest on thi 

 lace of craggy precipices. 



Genus THALTJUANIA, Gould in Proceed. Zool 

 Sue. 1848. 



Tn this genus the males are gorgeous, the 

 females plain. The throat gorget is generally 

 metallic green, succeeded by metallic blue ; the 

 nest is compact, placed on a twig, and coated 

 most elegantly with lichen ; the beak is acute, 

 longer than the head, and slightly arched ; the 

 wings are rather small ; the tail is ample, and 

 more or less forked; the feet are small and 

 delicate, and the tarsi are clothed with feathers. 



The type of this genus is the Fork-tailed 

 Humming-bird, described and figured in the 

 Naturalist's Lib. Ornith. vol. i. p. 125, pi. 24. 



