Mr. D. G. Elliot on the Trocliilidse. 37 



glittering feathers ; while the remaining species, nine in all, 

 have the crown dull in appearance, metallic hues showing in 

 only a very limited degree, even in strong lights. The genus 

 is closely allied to Cyanomyia ; but I do not agree with M. 

 Mulsant in placing such species as T. milleri, T. chionopectus , 

 T. viridiceps, T. leucogaster, and T. candidus in the genus Cy- 

 anomtjia, nor in subdividing the last-named genus into two 

 subgenera on account of the hues of their plumage. In 

 my opinion, colour alone should never . be made a character 

 for establishing a genus in ornithology, especially among the 

 Trochilidse, the species of which vary so notoriously in the 

 different shades of their plumage ; and for the same reason I 

 do not accept the term Leucolia, given to certain members of 

 the genus Thaumatias. 



The following analytical table will exhibit the more promi- 

 nent characters of the species of Thaumatias : — 



A. Throat and breast white. 



a. Top of head brilliantly metallic. 

 n'. Bill black. 



1, Tail purplish bronze 1. T. chionopectus. 



b'. Bill — maxilla black, mandible flesh-colour, 

 tip black. 



1. Tail steel-black, median feathers greenish 



bronze 2. T. leucogaster. 



2. Tail greenish grey, barred with brown 



near tip ; biU long, stout 3. T. viridiceps. 



3. Tail greenish grey, subterminal bar dark 



brown ; bill short, weak 4. T. millei'i. 



b. Top of head slightly metallic. 

 a'. Entire abdomen white. 



1. Tail greenish bronze, with a subterminal 



dark brown bar b. T. candidus. 



h'. Abdomen and flanks pale rufous 6. 7". norrisi. 



c'. Centre of abdomen white. 



1 . Tail pale bronze-greeu,barred with brown, 



tipped with dusky 7. T. brevirostris. 



2. Tail blue-black S. T. cotnpsa. 



B. Throat and breast metallic green. 

 a. Crown of head dull green. 



a'. Under tail-coverts pure white. 



1. Kectrices steel-black, median ones slightly 



tinged with gTeen iu certain lights . . 9. 7'. nigricmida. 



2. Median pair of reetrices golden green, 



