_Hirundo neoxena_, Gould in Proc. of Zool. Soc., Part X. p. 113. Genus CHELIDON, _Boie_. I find that by some unaccountable mistake I have placed the Australian members of this genus in that of _Collocalia_,—an error which I take this opportunity of correcting. The two species inhabiting Australia are both represented by others in Europe, Asia, Africa and America. They differ somewhat from each other in habits, one always resorting to the holes of trees for the purpose of nidification, and the other building a clay nest similar to those constructed by the martins of Europe and America. 53. Chelidon arborea. Collocalia arborea, _Gould_ Vol. II. Pl. 14. 54. Chelidon Ariel. Collocalia Ariel, _Gould_ Vol. II. Pl. 15. Family MEROPIDÆ, _Vig._ Genus MEROPS, _Linn._ India and Africa may be said to be the great nursery of this lovely group of birds; one species of which, common in the southern parts of Europe, is beautifully represented in Australia by the _Merops ornatus_, the only species inhabiting that country. 55. Merops ornatus, _Lath._ Vol. II. Pl. 16. Family ——? Genus EURYSTOMUS, _Vieill._ One species of this genus is found in Australia, and others inhabit India and Africa. They are closely allied to the Rollers, and not very distantly related to the Halcyons. 56. Eurystomus Australis, _Swains._ Vol. II. Pl. 17. Family HALCYONIDÆ, _Vig._ Genus DACELO, _Leach_. The members of the genus _Dacelo_ comprise the largest species of the great family of the _Halcyonidæ_, and form a conspicuous portion of the ornithology of Australia; but remarkably enough are confined to the south-eastern and northern portions of the country, the south-western parts being uninhabited by any species of this group. I believe that water is not essential to their existence, and that they seldom if ever drink. They feed almost exclusively upon animal substances, small quadrupeds, birds, snakes, lizards, and insects of every kind being equally acceptable. Three species inhabit Australia. 57. Dacelo gigantea Vol. II. Pl. 18. Inhabits the south-eastern portion of Australia, from South Australia to Moreton Bay. 58. Dacelo Leachii, _Vig. & Horsf._ Vol. II. Pl. 19. Inhabits the north-eastern portion of Australia, and is common at Cape York. 59. Dacelo cervina, _Gould_ Vol. II. Pl. 20. Inhabits the north-western parts of Australia, particularly the Cobourg Peninsula.