BIRDS OF NORTH AND MIDDLE AMERICA. 329 
Phxthornis adolphi (not of Gould) Rrpaway, Proc. U. S. Nat. Mus., iii, 1880, 
309, part (Turbo, n. Colombia; see Berlepsch, Proc. U. S. Nat. Mus., xi, 
1888, 560). 
Genus GLAUCIS Boie. 
Glaucis Bors, Isis, 1831, 545. (Type, Trochilus hirsutus Gmelin.) 
Medium-sized Trochilide (length about 100-110 mm.) very 
similar to Threnetes but differing in more strongly decurved, 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, distinctly to rather strongly decurved, about twice as 
long as head, the culmen rounded except for mesorhinal portion, 
where narrowly ridged; tomia smooth; maxilla and mandible with 
narrow median grooves. Nostril narrow, slit-like, overhung by a 
broad, tumid, operculum, feathered only on extreme upper basal 
portion. 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 than lateral toes, relatively 
weak. Wing less than twice as long as exposed culmen, the outer- 
most primary longest. Tail equal to (sometimes longer than) ex- 
posed culmen, strongly rounded or nearly graduated, the rectrices 
narrowly rounded terminally. 
Coloration.—Above metallic bronze or bronze-green, the pileum 
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 Ecuadér. (Several species.*) 
@ Owing to insufficiency of material I am not able to express an opinon as to the 
exact number of species which should be 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 occur 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 Panamé 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 Trinid4d, 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. 
