H1UUM)1NID.E — THK SWALLOWS. 397 



Bill ratlior weaker; coinniissrire and culineii nearly straiirlit to near tip. 

 Frontal feathers bristly. Tail nearly even. Tlin)at, rump, and erissiun, 

 and usually forehead, rufous ; belly wliite .... PrfrocJuliilon. 



h. Edp^e of wini.'' smooth. Tarsus loufjer than in last ; e(|ual to middle toe 



and half tin' elaw. Nostrils bordered alonj; posterior half by memlirane, 



but not overhun<^ internally. IJill very small. Tail forked. Crissum dusky 



except in Xeorht^/idou /ucafa. Various j,'enera and subi^enera, none Xorlh 



Ameriean, as Atticuru, Xotiorhelidoit, Xeorhelulon, and PijijachfUdon. 



r. Eci^'e of \vin<^ armed with stilf recurved hooks. Tarsus as in precedinjx 



(tarsus and toes nmeh as in Pt/f^ochelitfon). l>ill lar^'er and more depressed. 



Tail emarfjrinate only. Crissum white ...... StehjUlopterifx. 



B* N»>strils lateral; bordered behind and inside, or overhung by membrane, the 

 outer edge of which is straight, and directed either j)arallel witli axis of bill or 

 diverging from it. 



a. Tarsus short; about equal to middle toe without claw. Tibial joint feath- 

 ered ; feathers extending along inside of upper end of tarsus. 



Tarsus bare at lower end. Lat«Mal claws reaching onlv to base of 

 middle. 



Tail very deeply forked, much longer than closed wings: lateral 

 feathers linear and very narrow at end, twice the length of central. 

 Upper parts an<l pectoral collar steel-blue ; front .ind throat, some- 

 times under parts, rulbus. Tail-feathers with large spots . Hirumlo. 



Tail with shallow fork, not exceeding half an inch, shorter than 

 closed wings. Feathers broad. Color blue or green above, with 

 or without white rump ; white beneath. Tail-feathers without 

 spots . ......... Tachijchieta. 



Tarsus with a tuti of feathers at lower end. Lateral claws lengthened, 

 reaching beyond base of middle claw. 



Tail slightly forKed. Color dull-brown above; beneath white, 

 with brow'i pectoral collar ....... Coltfle. 



h. Tarsus long; equal to middle toe and half claw : entirely bare. Tail rttii- 

 siderably forked, about equal to closed wing. Color green above ; white 

 beueatU ........... CaUirheiidon} 



Genu.s FROGNE, BoiE. 



Progne, Boik, Lis, 1826, 971. (Type, Ilinuido purpurea vel suhis, L.) — Baiut), Bmls 

 N. Am. 185», yi I. 



(iKN. CnAK. Body stout. Bill n bust, lengtheneil : h^wer or commissural edge of max- 

 illa sinuated, decidedly convex for basal half, then as concave to the tip, the lower man- 

 dible falling within its chord. Nostrils superior, broadly <>[)en. and neaily circular, without 

 any adjacent membrane, the edges rounded. Legs stout, laisns equal to middle toe 

 without claw; the joint leathered : lateral toes about e<pi;»l ; the ba.^al joint of the mid- 

 dle toe half free internally, rather less so externally. Claws strong, much curved. Nest 

 in hollow trees. Eggs white. 



The s])ecies of this fjeniis are the most powerful and rol)ust of the Swal- 

 lows. Some are entirely glos^y-hlack, others whitish helow. The following 



1 Ilirundo {Call ichflidirn\ cyayicovirilis (Bryant), Baiko, Rev. Am. Birds, 1865, 303. Baha- 

 mas. This sjKicies may yet be detected ou the Florida coast. 



