BIRDS OF NORTH AND MIDDLE AMERICA. 531 



Thaluronia (misprint?) Gray, Gen. Birds, i, App., 1849, 5, in text. 



Glaucopes "Less[on]" Gray, Gen. Birds, i, Dec, 1848, 108, in text. (Type, 



Trochilus glaucopis Gmelin.) 

 Glaucopis BuRMEiSTER, Syst. Ueb. Th. Bras., ii, 1856, 333. (Type, Trochilus 

 glaucopis Gmelin.) 



Medium-sized Trochilidse (length about 95-115 mm. in adult males, 

 90-9S in adult females) with bill about as long as head, straight or 

 slightly decurved, the terminal portion of maxillary tomium serrated ; 

 nasal operculum mostly concealed, tail forked or (in females) emar- 

 ginate, with relatively broad lateral rectrices, the adult males with 

 under parts bright metallic green or (often) with under parts of body 

 violet and tail uniform blue-black or violet-black, the adult females 

 with under parts pale gray (under parts of body sometimes metallic 

 greenish), and lateral rectrices tipped with pale grayish (sometimes 

 greenish or grayish basally). 



Bill about as long as head, straight or slightly decurved, terete or 

 slightly broader than deep basally; culmen broadly rounded, but 

 basally contracted into a distinct narrow ridge; terminal portion of 

 maxillary tomium serrated ; mandible with a distinct lateral groove or 

 sulcus, the maxilla with indication of the same. Nasal operculum 

 rather narrow, mostly covered by frontal feathering, which forms 

 distinct antiie on each side of mesorhinium, extending forward at 

 least to middle of nasal operculum. Tarsus completely clothed with 

 short feathers; middle and inner toes about equal in length, the 

 outer slightly shorter, the hallux shorter than outer toe. Wing about 

 three times as long as culmen, the outermost primary longest. Tail 

 nearly as long as wing to less than two-thirds as long, forked in adult 

 males, emarginate or slightly forked in females, the lateral rectrices 

 relatively broad, all rather rigid, with rounded tip. 



Coloration. — Adult males metallic green or green with violet or 

 black (sometimes both) above, the forehead and crown sometimes 

 brilliantly metallic green or violet; tail uniform black, blue-black 

 or violet-black; chin and throat, sometimes chest also— in some 

 species whole or most of under parts — very bright metallic green, 

 the under parts of body usually rich metallic violet, in abrupt con- 

 trast. Adult females metallic green or bronze-green above, pale 

 gray beneath, the lateral rectrices tipped with pale gray and some- 

 times gray or greenish basally. 



Range. — Western Mexico to Cayenne, southeastern Brazil, Bolivia, 

 and Peru. (About sixteen species.) 



KEY TO THE SPECIES AND SUBSPECIES OP THALURANIA. 



c. Throat and chest bright metallic green; under parts of body metallic green, violet- 

 blue, or blackish. (Adult males.) 

 b. Lesser wing-coverts and anterior scapular region (sometimes upper back also) 

 violet or violet-blue: tail dark steel blue or dark violaceous-blue. 



