46 Mr. D. G. Elliot on the Trochilidse. 
Agyrtria compsa, Heine_, Jour, fur Ornitli. 1863_, p. 185, 
sp. 19. 
Hab. Guiana. 
This is, apparently, a very distinct species; but I am not 
autoptically acquainted with it. The authors of the Mu¬ 
seum Heineanum,’ referred it to the Trochilus mellisugus, 
Linn.; but Hr. Heine afterwards described it as distinct under 
the name of compsa {L c.). Although allied to T. brevi- 
rostris, it can easily be distinguished by the blackish-blue 
tail, that of the other species being bronze-green, and also 
by the under tail-coverts, which are said to be shining green 
(uniform?), those of T. brevirostris being dull green mar¬ 
gined broadly with white. Hrn. Cabanis and Heine state 
that it is smaller than T. brevirostris^ with a longer bill. 
Dimensions of this kind among birds of this family are not, 
however, of much specific importance; and the bird will pro¬ 
bably establish its claim to a separate rank, chiefly, I imagine, 
by the colour of the tail, a rather unusual one for a species 
belonging to the group in which it finds its place. 
I have had for a long time a Humming-bird belonging to 
this genus, which seems to have escaped the notice of orni¬ 
thologists, or else to have been confounded with some other 
species. It is not unfrequently met with in collections; but 
I have been entirely unsuccessful in finding any published 
name for it. I have a series of specimens from Trinidad, 
British Guiana, and Cayenne; and I have also seen an ex¬ 
ample in Graf von Berlepsch^s collection, the locality of which 
was stated to be Bahia. This would seem to give the species 
a rather extensive range along the eastern coast of South 
America. Belonging to the second group into which I have 
divided the genus, in the subdivision with white under tail- 
coverts, this species differs from all the other members of the 
genus in haviilg, together with pure white under tail-coverts, 
the entire tail a deep blue-black, the median rectrices having 
but the faintest tinge of green only in certain lights, and 
the lateral tail-feathers edged with white at their tips. I 
propose to call this species, having no recorded name by which 
to designate it. 
