CYPSELIB^^CH^TUBm^.: SPINE-TAIL SWIFTS. 457 



32. Subfamily CH^TURIN/E: Spine-tail Swifts. 



Toes with the normal number of phalanges; all but 

 the penultimate ones extremely short. Anterior toes oleft 

 to the base (no webbing). Hind toe not reversed, but 

 sometimes versatile; our species have it obviously ele- 

 vated. Tarsi never feathered ; naked and skinny, even 

 on the tibio-tarsal joint. In the principal genus, Chce- 

 twra, containing about half the species of the subfamily, 

 of various parts of the world, the tail-feathers are stiffened 

 and muaronate by the projecting rhachis. The other 

 genera are Collocalia and Dend/rochelidon of the Old 



cronat^tSi-feathef o™c^ffi«wrpSosff"ai World; CypseUMes, and the scarcely different Nephoece- 



nat. size. (Ad nat. del. B. C.) tes, of the New. 



132. NEPHCB'CETES. (Grr. vf<pos, nephos, a cloud ; olKerris, oiketes, an inhabitant : well applied to 

 these high-iiyers.) Cloud Swifts. Tail forked or emargiriate, with obtusely-pointed but non 

 mucronate stiffish feathers. First piimary longest. Tarsi naked, skinny. Hind toe elevated, 

 but perfectly posterior. Front toes cleft to the base. Nostrils embedded in feathers. Unicolor. 



404. N. ni'ger borea'lis. (Lat. niger, black; borealis, northern. Our species is a variety of the 

 West Indian N. niger. Fig. 296.) Northekn Black Cloud Swift. $ ? , adult. Entire 

 plumage sooty-black, with slight greenish gloss, little paler below than above, the feathers of 

 head and belly with grayish edges. A velvety black area in iront of eye ; forehead hoary ; eye- 

 lids partly naked. Bill black • t probably dusky-purplish in life. Length 6.60-7.00 ; wing 

 the same; tail 2.75, forked "early 0.50 in the adult (J, merely emarginate in the <? ; tarsus 

 0.50; middle toe and claw about the same. Young: Tail rounded; plumage dull blackish, nearly 

 every feather skirted with white, especially noticeable on belly, rump, and upper tail-coverts and 

 inner wing quills ; crissum mostly white ; supposed to require several years to perfect the black 

 plumage. Eocky Mts. to the Pacific, U. S. and British Columbia ; a great black swift still 

 little known ; supposed to nest in cliffs up to 11,000 feet ; ranges to about 13,000 ; crops found 

 filled with Ephemerida. 



133. CH.iETU'BA. (Gr. x""'"?; chaite, a bristle; ovpa, oura, a tail. Fig. 297.) Spine-tail 

 Swifts. Tail short, less than half as long as wing, even or a little rounded, mucronate, — -the 

 stiff spiny shafjs of the feathers protruding lilce needles beyond the webs. First primary longest. 

 Tarsi naked and skinny. Hind toe elevated, but posterior. Front toes all of about the same 

 length, cleft to the base. Feathers reaching to but not far below the nostrils. Unicolor or 

 bicolor (our species one-colored, sombre). Sexes alike. 



405. C. pelas'gica. (Gr. UeKaayoi, the Pelasgoi, a nomadic tribe ; Lat. pelasgica, i. e., migratory.) 

 Chimney Swift. Chimney "Swallow." Sooty-brown, with a faint greenish gloss above ; 

 below paler, becoming gray on the throat ; wings black ; a velvety black space about eyes. 

 Length about 5.00; wing the same; extent about 12.50; tail 2.00 or less, even or a little 

 rounded, spiny. Eastern U. S., migratory, very abundant in summer. Like the swallovfs, 

 which this bird so curiously resembles, not only in its form, but in its mode of flight, its food, 

 and twittering notes, it has mostly forsaken the ways of its ancestors, who bred in hollow trees> 

 and now places its curious open-work nest, of bits of twig glued together with saliva, inside 

 disused chimneys, in settled parts of the country. In districts still primitive, however, it con- 

 tinues to use hollow trees, to which it resorts by thousands to roost. Not impossibly winters 

 in such retreats in a lethargic state ! The twigs for its pretty basket-like nest are snapped off 

 the trees by the birds in full flight. The eggs are 4-5, 0.75 to 0.80 long by 0.53 broad, thus 

 narrowly elliptical, and pure white. So great are the voUtorial powers of this bird, that the- 

 sexes can come together on the wing. 



