BIRDS OF NORTH AND MIDDLE AMERICA. 27 



dd. Basal phalanx of middle toe entirely adherent to outer toe. 

 i'. Tibio-tarsal joint entirely hidden by tibial feathers; edge of outermost 

 primary roughened by recurved tips to the barbs (except in young and 

 Home females) ; upper parts dull grayish brown (sometimes dull whitish 

 on rump) ; under parts neither uniform sooty gray nor partly black." 



Stelgidopteryx (p. 56) 



ee. Tibio-tarsal joint exposed; edge of outer primary normal (not roughened) ; 



upper parts never entirely grayish brown nor with whitish on rump; 



under parts sooty gray or brown, or with more or less of black. 



/. Tail much less than two-thirds as long as wing, forked for less than 



one-fourth its length (sometimes nearly even), the lateral rectrices 



broad; nasal fossae occupying at least basal half of maxilla; under 



parts sooty gray, becoming black on under tail-coverts or dull white, 



becoming sooty gray on throat Orochelidon (extralimital) 6 



ff. Tail more than three-fourths as long as wing, forked for half its length, 

 the lateral rectrices narrow and attenuate; nasal fossae very small, 

 occupying much less than basal half of maxilla; under parts pure 

 white, with under tail-coverts and band acrgss chest glossy blue- 

 black Diplochelidou (extralimital) « 



cc. Subbasal phalanx of middle toe adherent for basal half to outer toe (the 

 basal phalanx of course entirely adherent). 

 d. Basal phalanx of middle toe with only the basal half adherent to inner 

 toe; tibial feathers short, not covering tibio-tarsal joint, not white; back 

 grayish brown ; under parts of body largely white . .Notioohelidon (p. 65) 

 dd. Basal phalanx of middle toe adherent for most of its length to inner toe; 

 tibial feathers full, covering tibio-tarsal joint, white, forming a conspicu- 

 ous tuft; back not grayish brown or else under parts of body without 

 any white, 

 c. Tail about half as long as wing, forked for less than one-fourth its length; 

 hallux much shorter than inner toe; wing-tip much shorter than dis- 

 tance from bend of wing to tip of longest secondaries; above sooty 

 blackish becoming grayish brown or sooty gray on rump; beneath 



sooty brown Neochelidou (p. 67) 



ee. Tail at least two-thirds as long as wing, forked for nearly half its length; 

 wing-tip equal to or longer than distance from bend of wing to tip of 

 longest secondaries; hallux as long as inner toe; uniform glossy blue- 

 black with a broad white band across lower breast. 



Atticora (extralimital).** 

 aa. Nostrils opening laterally, in lower portion of nasal fossae, narrow, longitudinal, 

 overhung by a broad membraneous operculum (this sometimes entirely covered 

 ' by feathers). 



« Except, sometimes, a blackish spot or longer under tail-coverts. 



b Orochelidon., new genus. (Type, Petrochelidon murina Cassin, =Hirundo cinerea 

 Gmelin?) There is considerable difference in form between 0. murina (cinerea^) 

 and 0. andicola, the latter having a nearly even instead of deeply emarglnate or 

 forked tail and much less depressed bill. (Andean region of Ecuador, Peru, and 

 Bolivia; two species.) ('Ofioi, a mountain; x^'^iSd)v, a swallow.) 



" Diplochelidon, new genus. (Type, Hirwndo melanoleuca Maximilian.) {^inXdoi, 

 double; ;(£/li5(»i', a swallow; with reference to its resemblance to swallows of two 

 different types. ) South American (monotypic). 



dAtticwa Bole, Isis, 1844,172. (Type, Hirundo fasdata Gmelin.) South Amer- 

 ican (monotypic). 



