Mr. D. G. Elliot on the Trochilidse. 
37 
glittering feathers; while the remaining species^ nine in all^, 
have the erown 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. cMonopectus, 
T. viridiceps, T. leucogaster, and T. candidus in the genus Cy¬ 
anomyia, nor in subdividing the last-named genus into two 
suhgenera 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 
Trochilidae, the species of which vary so notoriously in the 
diflPerent 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. 
a'. Bill black. 
1. Tail purplish bronze.. 
h'. Bill—maxilla black, mandible flesh-colour, 
tip black. 
1. Tail steel-black, median feathers greenish 
bronze . 
2. Tail greenish grey, barred with brown 
near tip j bill long, stout. 
3. Tail greenish grey, subterminal bar dark 
brown j bill short, weak . 
b. Top of head slightly metallic. 
a'. Entire abdomen white. 
1. Tail greenish bronze, with a subterminal 
dark brown bar. 
h\ Abdomen and flanks pale rufous . 
c'. Centre of abdomen white. 
1. Tail pale bronze-green,barred with brown, 
tipped with dusky. 
2. Tail blue-black ...!.. 
B. Throat and breast metallic green, 
a. Crown of head dull green. 
a'. Under tail-coverts pure white. 
1. Rectrices steel-black,median ones slightly 
tinged with green in certain lights . . 
2. Median pair of rectrices golden green. 
1. T. chionopectus. 
2. T. leucogaistei\ 
3. T. viridiceps. 
4. T. milleri. 
5. T. candidus. 
6. T. norrisi. 
7. T. brevirostris. 
8. T. compsa. 
9. T. nigricauda. 
