I have alluded to the great wing-powers of the birds of the genus _Acanthylis_, and in confirmation of which I may mention that an individual of this species was killed in England during the past year: it would be interesting to know the route pursued by the bird in travelling so great a distance as it must have done. Genus CYPSELUS, _Ill._ Of this genus, as of _Acanthylis_, there is but one species peculiar to Australia: other members of the group inhabit the continents of Europe, Asia and Africa, but not America. 50. Cypselus Australis, _Gould_ Vol. II. Pl. 11. _Hirundo pacifica_, Lath.? Genus ATTICORA, _Boie_. The members of this genus are principally American. I am not fully satisfied of the propriety of placing the bird I described in the ‘Proceedings of the Zoological Society’ as _Hirundo leucosternon_ in the present genus: if on a further knowledge of the Australian birds it should prove that I have been correct in so doing, the species will be found to inhabit Australia, Africa and America. 51. Atticora leucosternon, _Gould_ Vol. II. Pl. 12. Since I described and figured this species I have received numerous examples from Swan River, where Mr. Gilbert observed it on the 19th of August flying about the holes of the Boodee (_Bettongia Grayii_) in pairs; but it was not until the latter end of September that he succeeded in finding their nests placed at the extremities of holes bored in the side of a bank. All the holes that he saw were perfectly round, not more than two inches in diameter, running horizontally, and of the same dimensions, for three feet from the entrance, and then expanding to the extent of four inches and forming the receptacle of the nest, which is constructed of the broad portions of dried grasses and the dry dead leaves of the Acacia. Mr. Johnson Drummond informed him that he had frequently found seven and even nine eggs in a single nest, from which he inferred that more than one female lays in the same nest: the eggs are white, somewhat lengthened, and pointed in form. It would seem that the holes are not constructed exclusively for the purpose of nidification, for upon Mr. Gilbert’s inserting a long grass stalk into one of them five birds made their way out, all of which he succeeded in catching; upon his digging to the extremity in the hope of procuring their eggs, no nest was found, and hence he concludes that their holes are also used as places of resort for the night. Genus HIRUNDO, _Linn._ The members of the genus _Hirundo_, or true Swallows, inhabit Europe, Asia, Africa, North America, the Indian Islands and Australia, where the European and American chimney Swallows, _Hirundo rustica_ and _H. rufa_, are beautifully represented by the _H. neoxena_. 52. Hirundo neoxena, _Gould_ Vol. II. Pl. 13.