Mr. D. G. Elliot on the Trochilidse. 
405 
Petasophora coruscans. 
Petasophora coruscans, Gould, P. Z. S. 1846, p. 44; id. 
Mon. Troch. vol. iv. pi. 226 ; id. Intr. Troch. (8vo ed.) p. 125. 
sp. 251. 
Hab. -? 
For a long time this bird has been a puzzle to me. I do not 
altogether like its appearance as a species ; hut at the same time 
I cannot exactly understand what may have caused the pecu¬ 
liar coloration of the throat. I have only seen two speci¬ 
mens—one in Mr. Gould^s collection, from which his figures 
were taken, and one in my own, precisely similar, as was 
proved on comparing the two together. These are the only 
examples, I believe, that have ever been procured; and the 
locality of neither is known. My specimen came in a large 
lot of about 4000 birds, nominally from Bogota; and there 
was no other in any way resembling it, although careful 
search was made. I have tried the effect of heat upon other 
specimens of Petasophora, to see if I could change the green 
metallic colours to the red so conspicuous on the throat of 
P. coruscans, but without success; and I know of no acid with 
which the bird in life or the skin afterwards would be likely 
to have come into contact, that would produce the change. 
With only a single specimen for us to form an opinion, we 
should, not unnaturally, decide that it was a curious individual 
variation; but with two exactly alike, it would seem strange 
that so peculiar a difference should have been produced acci¬ 
dentally; and if it had been, the thought naturally arises, Why 
does it not occur oftener among the thousands of specimens 
of the different species of Petasophora constantly brought to 
Europe ? That a similar style does exist, in one other in¬ 
stance, is proved from the fact that I have an example of 
Petasophora in my collection smaller than coruscans, and 
evidently not the same species, which has the entire throat 
a bright metallic red. This colour does not spread to the 
chest, as is the case with the similar colour in P. coruscans, 
but is restricted to the centre of the throat, which it entirely 
covers. Now if P. coruscans is a distinct species, this unde- 
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