(at least posteriorly) by an extension of the membraneous integument of the nasal fossæ an intornal tubercle or facet visible within the posterior portion. Rictal bristles present, but inconspicuous; feathers of chin, malar antiæ, and loral region with distinct terminal setæ. Wing moderate or rather large, with longest primaries extending decidedly beyond secondaries; sixth and seventh, or seventh, primaries longest, the tenth (outermost) three-fifths as long as the longest, or slightly more, the ninth equal to or slightly longer than secondaries. Tail slightly more than one-half to three-fifths as long as wing, slightly rounded, the rectrices (12) rather broad, rounded terminally. Tarsus much longer than whole culmen, a little less than two-fifths as long as wing, the acrotarsium indistinctly scutellate (scutella sometimes obsolete except on lower portion), the planta fused, at least for greater part; middle toe, with claw, much shorter than tarsus; outer toe, without claw, reaching to about middle of subterminal phalanx of middle toe, the inner toe decidedly shorter; hallux equal to or slightly longer than inner toe; basal phalanx of middle toe wholly united, the second phalanx partly united, to outer toe (the adhesion involving the first two phalanges of outer toe), united for half its length or more to inner toe; claws rather large, moderately curved, extremely compressed, that of the hallux shorter than the digit (but sometimes nearly as long). Plumage full, soft, and blended, that of rump and flanks more elongated and lax; feathers of pileum not elongated.
Coloration. — Adult males gray and black above, the back with white spots or lunulate bars, the wing-coverts, tertials, and tail tipped with white; or back rufous or chestnut, with a concealed patch of white, the wing-coverts, tertials, and tail tipped with cinnamon- rufous; throat black, rest of under parts white, passing into gray or buffy on flanks, the chest spotted with black, or whole under parts plain gray. Adult females somewhat like males, but browner above with markings fulvous or bufFy instead of white, the throat whitish, and black markings of chest replaced by brownish, or (in slate- colored species) head and under parts rufescent or the general color of under parts gray, with white throat and dusky flanks.[1]
Range. — Costa Rica to western Ecuadór, Amazon Valley, and Guiana. (Six species?)[2]
- ↑ On account of insufficiency of material, I am not able to give the full range of color variation in this group.
- ↑ Of the species referred to the genus Hypocnemis by Dr. Sclater and other recent authors I have seen in this connection only H. cantator (type of the genus), H. pœcilonota (Cuvier), H. lepidonota Sclater and Salvia, H. leucophrys (Tschudi), H. myiotherina (Spix), H. lugubris (Cabanis and Heine), H. nævia (Gmelin), and H. nævioides (Lafresnaye). The second, third, seventh, and eighth of these I have removed from Hypocnemis on account of the very different amount of adhesion of the anterior toes and other excellent structural characters, while the fourth, fifth, and sixth I also remove as a distinct genus, Myrmoborus Cabanis and Heine. (See p. 14.)
There is much difference in the form of the bill between the three species of Hylophylax which I now have before me, H. nævia having this member very broad and very much depressed basally, while that of H. pœcilonota is much narrower, less depressed, and with the base of the gonys more prominent, H. nævioides being, however, intermediate between these extremes.
