Genus COTILE. 
Hirundo apud Linneus, Syst. Nat. i. p. 344 (1766). 
Cotyle, Boie, Isis, 1822, p. 550. 
Chelidon apud Boie, ut supra. 
Siblis apud Lesson, Compl. Buff. viii. p. 495 (1837). 
Cotile apud C. L. Brehm, J. f. Orn. 1853, p. 452. 
Ptyonoprogne apud Hume, Stray Feathers, i. p. 1 (1872). 
Tue genus Cotile is, as will be seen by the generic characters given below, not only fairly 
separable from Hirundo and Chelidon, but it might even with some degree of justice be further 
subdivided by separating Cotzle rupestris and Cottle obsoleta, though I have not thought it 
advisable to do so. These two species differ in their mode of nidification and in their eggs 
from Cotile riparia; and they have, moreover, the tarsi quite bare as in Hirwndo, though 
scutellate on the anterior surface. Had I decided to separate these two species from Cotile 
riparia, 1 should have had either to include them in the genus Hirundo, or else to separate them 
still further by placing them in the genus Bidlis, Lesson. 
The genus Cotile is represented in the Palearctic, Ethiopian, Oriental, Nearctic, and 
Neotropical Regions, three species being found within the limits of the Western Palearctic 
Region. These birds are entirely insectivorous, capturing their prey on the wing; and, like 
their allies, they are swift and strong in flight, but unable to move about on the ground owing to 
their small and feeble legs and feet. Their note is a somewhat feeble twitter; and they have 
no song, except a modulation of their usual note. Cotile riparia makes a nest of straws and 
feathers, which it places in a hole in a bank or cliff, and deposits pure white eggs; whereas Cottle 
rupestris and Cotile obsoleta build hemispherical nests of clay lined with feathers, which they place 
against a rock or building, and deposit white eggs spotted with red. 
Cotile riparia, the type of the genus, has the bill as in Chelidon, the nostrils basal, concealed 
by short feathers; gape furnished with a few short bristles; wings very long, pointed, the first 
quill longest; tail deeply forked, though less so than in Chelidon; tarsus and toes feeble, the 
tarsus covered in front with four larger and three inferior scutelle, and slightly feathered on the 
posterior side; claws rather long, curved, very acute and slender; plumage soft, the upper parts 
of the body dull brownish, and not dark-coloured and metallic-glossed as in Hirundo and 
Chelidon. 
In the articles on the species included in this genus I spelt the generic title Cotyle; but 
Mr. Wharton has shown (Ibis, 1879, p. 451) that this is a mistake, and that the correct 
orthography is Cottle. 
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