AGYRTRIA NIGRICAUDA. 



Black-tailed Emerald. 



Thaumatias nijricauda, Elliot, Ibis, 1878, p. 47. 



Agijrtria nigricauda, Elliot, Synopsis of the Humming-Birds, p. 208 (1878) 



Mr. Elliot, who originally placed this species in the genus Thaumatias, has, in his larger work, referred 

 it to Agijrtria. It differs from all the foregoing members of the genus in having the under tail-coverts 

 pure white. The tail is steel-black, with a tinge of green on the centre tail-feathers under certain lights. 



The home of this species, according to Mr. Elliot, is Guiana, Trinidad, and North-eastern Brazd. 



The following is the description given by the above-named gentleman : — 



" Upper parts bronzy green, darkest on the head, and shading into purple on the upper tail-coverts. 

 Throat and breast shining metallic grass-green. Flanks dark green, with scarcely any lustre. Middle of 

 abdomen, vent, and under tail-coverts pure white. Tail steel-black, the two outermost feathers greenish 

 grey at their tips, the next merely edged with white at the tip. Maxilla brownish black ; mandible 

 flesh-colour, the tip black. Feet black. Total length 3i inches, wing 2i tail U, bill along culmen I." 



[R. B. S.] 



AGYRTRIA NITIDICAUDA 



Brig-lit-tailed Emerald 



Thaumatias nitidicaiida, Elliot, Ibis, 1878, p. 48. 



Agyrtria iiitidicanda^ Elliot, Synopsis of the Humming-Birds, p. 208 (1878) 



This species, which comes from Guiana, is said by Mr. Elliot to resemble A. nigricauda, but to differ 

 in the colour of the tail. The median pair of rectrices are golden green ; the remaining ones with the 

 inner webs black, except the tip, the outer webs metallic golden green ; all the lateral tail-feathers are 

 tipped with bright metallic golden green. 



He further describes the species from the type in his collection : — 



''Adult. Upper parts bright bronzy green, with a slight coppery tinge on the head. Chin white. 

 Throat, breast, and sides of the neck bright metallic grass-green. Flanks and abdomen dull green. 

 Middle of abdomen, vent, and under tail-coverts pure white. Wings purplish brown. Bill flesh-colour 

 (perhaps red in life), with a dark tip. Total length 3i inches, wing 2i tail H, bill along culmen I." 



[R. B. S.] 



