HIR UNDINID.E : S WA LL WS. 



353 



reoriim Barton, 1799; Baird, J858; Coues, 1872, in 1st ed. of the Key; H. eri/tJirogasfra 

 horreonim of other eds. of the Key; Chelidon enjthrogasier, A. 0. U. List, 188(i, p. 292, 

 wrong for genus and wrong for gender; C erytlirogastra, A. 0. U. List, 2d ed., 1895, p. 258, 

 Nt). 613. This means that attempts to distinguish the North American bird from that of 

 South America have finally failed. 



TACHYCINE'TA. (Gr. TaxvKivqros, tachiikmetos, moving rapidly.) Iris Swallows. 

 Violet-velvet Swallows. Similar to the last, but lacking elongation and attenuation of 

 lateral tail-feathers, which also lack white spots. Tail simply emargiuate. Under parts 

 snowy white. Sexes alike. Eggs S-G, colorless. Ividoprocne and Taclujcineta of 2d, 3d, 

 and 4th eds. of the Key, p. 322. 



Analysis of Subgenfi-a and Species. 



Iridoprocne. Plumage of upper parts lustrous aud uuicolor .... 

 Tachyclneta proper. Plumage of upper parts lustreless and versicolor 



. biro 

 (li/iiass, 



Swallow. 

 Ln-es black. 



T. (I.) bi'folor. (Lat. hicolor, two-colored. Fig. 209.) White-bellied 

 Adult ^ : Entire upper parts glossy dark green ; wings aud tail blackish, lustrous; 

 Entire under parts pure white. Bill black ; feet dark. 

 Length about 0.00; extent 13.00; wing 4.50-5.00; 

 tail 2. .50. 9 : Similar, the colors rather less intense 

 aud lustrous. Young : Birds of the year slowly acquire 

 a plumage differing only in less lustre and intensity 

 from that of adults; but, (m leaving the nest, they are 

 dark mouse-gray or slate-color above, including wings 

 and tail; interscapulars and inner quills tipped with \ ^ 



rusty; white below, slightly shaded with ashy: thus 

 curiously similar to Clivicola riparia. Feet yellow. 

 The first plumage is worn longer than usual, the 

 autumnal dress being slowly gained — one or two of the Fig. 200. — White-beliied Swallow, nat. 



metallic-tinted feathers at a time. The quills of the «'"«• ^^^- "''*• <^'^^- ^- ^'^ 

 wing are moulted by the young as well as by the adult, and in both, in autumn, the ii.ner 

 secondaries are white-tipped. Temperate N. Am. Breeds indifferently in most parts of its 

 range, aud winters abundantly on the southern border, sometimes even from South Carolina, 

 to tlie West Indies and Cent. Am. 



T. thaias'sina. (Gr. BoKacra-Lvo^, thalassinos, sea-green.) Violet-green Swallow. Adult 

 ^ : Entire under parts, including sides of head to just above eyes, and an enlarged fluffy tuft 

 on flanks tending to join its fellow over rump, pure silky white. Upper parts rich velvety- 

 green, mixed with a little vicdet-purple ; crown of head similar, but rather greenish-brown, 

 with purplish tinge. Cervical region, in some cases a well-defined though narrow cervical 

 collar, and u])])er tail-coverts, violet-purple. These rich colors opaque, without gloss or sheen ; 

 wiiiiTS and tail blackisli, with violet and i)ur])lish gloss. Bill black ; feet brownish- black, 

 small; iris brown; mouth pale yellow. Length 4.50-5.50; extent 11.50-12.50; wing 4.50; 

 tail 2.00, lightly forked; bill 0.25; tarsus 0.40. The 9 , and immature birds in general, differ 

 simply in less purity and intensity of colors of ujjper parts. In highest plumaged specimens, 

 tlu- back is nearly pure green, the cervical collar distinct, and tiie several contrasts of crown, 

 collar, back, and upper tail-coverts are strong; in general, the back has a brownish-purple 

 sliade, more like that of crown. Very young birds are like 1'. hicolor, though smaller, being 

 dark mouse-gray above and white btdovv. But traces at least of the special tints speedily ap- 

 ])ear. Young or autumnal birds usually have the inner secondaries whit('-tipi)ed, as in T. hicolor. 

 Mid.llc and Western Provinces, U. S., and a<ljoining portions of British America; E. to the 



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