Delichon is an Old World genus with all three species breeding only in the northern hemisphere.
From the en.wikipedia.org
Delichon is a small genus of passerinebirds that belongs to the swallow family and contains three species named as house martins.
From the en.wikipedia.org
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A genus of Hirundinidae
Delichon is a genus of passerine birds that belongs to the swallow family and contains three species named as house martins. These are chunky, bull-headed and short-tailed birds, blackish-blue above with a contrasting white rump, and with white or grey underparts. ...