BIEDS OF NORTH AND MIDDLE AMERICA. 329 



Phsethornis adolphi (not of Gould) Ridgway, Pror. U. S. Nat. Mus., iii, 1880, 

 309, part (Turbo, n. C'oloml)ia; s^ee Berlepsch, Proc. U. S. Nat. Mus., xi, 

 1888, 560). 



Genus GLAUCIS Boie. 



Glands Boie, Isis, 1831, 545. (Type, Tmchilus hirsutus Gmelin.) 



Medium-sized Trocliilid» (length about 100-110 mm.) very 

 similar to Tlirenetes but dilTering in more strongly decurvetl, much less 

 depressed (narrower), and relatively longer bill, wholly nude nasal 

 operculum, unicolored under parts, and basal half of rectrices chest- 

 nut or rufous instead of white or buff. 



Bill rather slender, compressed, scarcely if at all broader than 

 deep basally, distmctly to rather strongly decurved, about twice as 

 long as head, the culmen rounded except for mesorhinal portion, 

 where narrowl}" ridged; tomia smooth; maxilla and mandible wdth 

 narrow^ median grooves. Nostril narrow^, slit-like, overhung by a 

 broad, tumid, operculum, feathered only on extreme upper basal 

 })ortion. Tarsus mostly naked (feathered on upper portion in 

 front), longer than middle toe without claw, the latter slightly longer 

 than both lateral toes; hallux shorter tlian lateral toes, relativel}^ 

 weak. Wing less than twice as long as exposed culmen, the outer- 

 most primary longest. Tail equal to (sometimes longer than) ex- 

 posed culmen, strongl}' rounded or nearly graduated, the rectrices 

 narrowdy rounded terminally. 



Coloration. — Above metallic bronze or bronze-green, the pfleum 

 dull dusky; rectrices (except middle pair) with basal half rufous or 

 chestnut, then black tipped with whitish; under parts plain grayish 

 brown to cinnamon-rufous. Sexes essentially alike. 



Range. — Costa Rica to Guiana, Grenada (Lesser Antilles), Brazil, 

 and Ecuador. (Several sijccies.") 



a Owing to insufficiency of material I am not able to express an opinon as to the 

 exact number of species which should \>e recognized; but careful examination of a 

 considerable series (71 specimens) shows that G. hirsuta is by no means uniform 

 in characters throughout its range, and that three well-marked forms occm- within 

 the geographic limits of 'this work; namely, (1) a very small form (perhaps specifically 

 distinct), in which (alone) the sexes are apparently always alike in coloration of 

 the under parts and the color of the upper parts always decidedly bronzy, confined 

 to Nicaragua and Costa Rica; (2) a larger form with the adult male always much 

 duller in color of the under parts than the adult female and the upper parts less 

 bronzy, found in Panamd and adjacent parts of South America; and (3) a very large 

 form, essentially like the last in coloration, but more closely resembling (and here 

 not separated from) the smaller true G. hirsuta of the adjacent mainland, peculiar 

 to the islands of Trinidtid, Tobago, and Grenada. 



A very much larger series of specimens from various parts of South America is 

 required for the proper working out of the geographic variations in this species, and 

 the arrangement here given is to be considered as tentative only. 



