46 Mr. D. G. Elliot on the Trochilida. 



Agyrtria compsa, Heine^ Jour, fiir Ornith. 1863, p. 185, 

 sp. 19. 



Hab. Guiana. 



This is, apparently, a very distinct species ; but I am not 

 antoptically acquainted with it. The authors of the ' Mu- 

 seum Heineanum/ referred it to the Trochilus meUisugus, 

 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, ^flrn. 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 having, together Avith 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. 



