CYPSBLID^ — THE SWIFTS. 



431 



Gends CH^TURA, Stephens. 



Clmtura, STEniF.N-s, Shaw's Geii. Zool. Binls, XIII, ii, 182:), 76 

 Aainthiilis, BoiK, Isis, 1826, 971. {C'lfpsrlm x^rinicjmihi.) 



(Typp, C. pdcujim.) 



ClifTtura peln^irn. 



Gkn. Cii.u!. Tail very .*liort, scarcely more than two lifth.s the wings ; sliglitlv roundud ; 

 the shafts stiflened and ex- 

 tending some distance beyond 

 the feathers in a rigid spine. 

 First primary longest. Legs 

 covered liy a naked .skin, 

 without scutelUe or fcathor.<;. 

 Tarsus longer than middle 

 toe. Lateral toes equal, 

 nearly as long as the middle. 

 Hind toe scarcely versatile, 

 or quite posterior ; including 

 claw, les-s than the middle anterior without it. Toes slender ; claws moderate. Feathers 

 of the base of the bill not extending beyond the beginning of the nostrils. 



By the arrangement of the genera on page 1018, the C. rutila and large 

 wliite-collared species are excluded from the present genns as restricted. 

 Chcvtura, as here defined, is a genus of very extensive distribution, species 

 occurring not only in X(.ivtli and South America, but also in Africa aiid Asia. 

 Among the several American members, three styles are distinguishable, 

 these probaljly representing only as many species ; the several more closely 

 allied forms being, in all probability, but geographical modifications of these 

 three types. They may be arranged as follows : — 



Plumage with no marked contrasi of shades. 

 C. pelagica. Nearly uniformly dusky grayish-brown, the throat, however, 

 very much lighter, and the rump just appreciably so. 



Above glossy dusky-brown, hardly appreciably paler on the rump ; 

 abdomen scarcely paler than the back. Wing, 5.20. Ilab. Eastern 

 Province North America ....... var. pelagica. 



Above glos,sy blackish-dn.sky, very decidedly paler on the rump ; 

 abdomen very much paler than the back. Wing, 4..j0. Hah. Pacific 

 Province of North America, south to Guatemala (from whence speci- 

 mens are much darker, almost black above, and slightly smaller) var. vauxi. 



Above glossy black, fading into sooty dusky on the rump ; abdomen 

 like- the rump. Wing, 4.80. Hah. Northern South America (Cayenne, 

 Tobago) .......... var. jyol i u r u .' 



Plnmage with marked contrast of shades. 

 C. cinereiventris.' Upper parts, except the rump, glossy, intense blue- 

 black ; rump and lower parts bluish-cinereous, conspicuously diflerent. 



1 Chatura pnliurn, (Temm.) Scl. Cat. Am. B. 1862, 101 ; P. Z. 1^. 1S66, Gil. (Ci/psdus 

 polinirus, Temm. Tab. Meth. p. 78.) 



2 Chtelura cinercirentri<!, SoL. Cat. Am. B. 1862, p. 283 ; P. Z. S. 1863, p. 101, pi. xiv, f. 1 ; 

 P. Z. 1866, 612. C. sclateri, Pelz. Orn. Braz. I, 1868, pp. 16, 56, is also referrible to it as 

 perhaps a race. 



