The upper and under surface has not so strongly a marked purple shade, as in the _P. purpurea_. The primaries and feathers of the tail, however, have a greenish gloss, perhaps slightly more metallic. Tail not so deeply forked as in _P. purpurea_, which is owing to the two external feathers on each side not being so much prolonged and bent outward, as in that species. Nostrils of less size than in the latter, although the beaks differ but little. Claws and feet are much less strong, than might have been anticipated, even proportionally to the less dimensions of this species compared with the _P. purpurea_. Inches. Total length 6 Wings 5¼ Tail 2¾ Tarsi ½ Middle toe from tip of claw to joint ³⁵⁄₁₀₀ Habitat, James Island, Galapagos Archipelago, (_October_). _Male._ This swallow was observed only on this one island of the group, and it was there very far from common. It frequented a bold cliff of lava overhanging the sea. Had not Mr. Gould characterized it as a distinct species, I should have considered it only as a small variety, produced by an uncongenial site, of the _Progne purpurea_. I can perceive no difference whatever from that bird, excepting in its less size, slenderness of limbs, and less deeply forked tail; and the latter difference may perhaps be owing to youth. 1. HIRUNDO LEUCOPYGIA. _Licht._ My specimens were obtained at Port Famine, in Tierra del Fuego, (_February_), and at Valparaiso, in Chile, (_August to September_). At Port Famine they build in holes in a cliff of earth. Mr. Gould says, “were it not for the bare legs of this little Martin, I should have some difficulty in discriminating between it and the one so well known as a summer visitor in our island.” 2. HIRUNDO FRONTALIS. _Gould._ _H. vertice, plumis auricularibus, dorso et lunulâ pectorali nitidè cæruleo viridescentibus, notâ albâ supra nares, gulâ corporeque subtus albicantibus, crisso niveo, alis caudâque fuscis viridi tinctis, rostro nigro, pedibus intensè fuscis._ Long. tot. 4¾ unc.; _alæ_, 4¾; _caudæ_, 2; _tarsi_, ½. Upper surface, with a greenish blue metallic gloss; which can faintly be perceived on the primaries and on the tail feathers. The short feathers over each nostril white, thus forming two small white marks; those over the ridge of bill pale brown, giving together the appearance of a narrow white band over the upper mandible. Entire under surface and lining of wings pure white. Tarsi rather darker than in _H. leucopygia_. Very slightly larger than _H. leucopygia_; upper mandible rather broader.