A group inhabiting every part of Australia, and probably New Guinea and Polynesia. Their chief food consists of insects of the most diminutive size, such as aphides, gnats and mosquitos. The more thickly-billed species may probably feed upon larger insects and their larvæ. They mostly frequent the thick umbrageous woods, where they dart about for insects under the canopy of the dense foliage, or sally forth into the open glade like true Flycatchers. Their nests are of a domed form, with the entrance near the top, some species protecting the opening by constructing a projection above it like the eaves of a house; the eggs are generally four in number, and spotted with red like those of the _Maluri_ and _Pari_. 146. Gerygone albogularis, _Gould_ Vol. II. Pl. 97. _Psilopus olivaceus_, Gould in Proc. of Zool. Soc., Part V. p. 147, Young. 147. Gerygone fusca, _Gould_ Vol. II. Pl. 98. 148. Gerygone culicivorus, _Gould_ Vol. II. Pl. 99. 149. Gerygone magnirostris, _Gould_ Vol. II. Pl. 100. 150. Gerygone lævigaster, _Gould_ Vol. II. Pl. 101. 151. Gerygone chloronotus, _Gould_ Vol. II. Pl. 102. Genus SMICRORNIS, _Gould_. Generic characters. _Bill_ very small and short, swollen at the sides; _nostrils_ basal, oblong and protected by an operculum; at the base of the bill a few fine hairs; _wings_ moderately long, first quill very short; the first, third, fourth and fifth equal and the longest; _tail_ short and square; tarsi moderate; _toes_ rather short, adapted for clinging; the hinder and the middle toes equal in length. The members of this genus are the smallest birds of the Australian fauna. I have described two species, one inhabiting New South Wales and the other Port Essington; and had I characterized the bird of this form inhabiting Western Australia as distinct, I should most likely not have been in error, as it is probable that when the subject has been more fully investigated it will prove to be so. 152. Smicrornis brevirostris, _Gould_ Vol. II. Pl. 103. 153. Smicrornis flavescens, _Gould_ Vol. II. Pl. 104. Family SYLVIADÆ, _Vig._ Subfamily SAXICOLINÆ, _Bonap._ Genus ERYTHRODRYAS, _Gould_. Generic characters. As in _Petroïca_, but with the _bill_ shorter and more flattened at the base, where it is beset with a number of fine hairs which curve forward and overhang the nostrils; _wings_ shorter and more rounded; first and second primaries much shorter than the rest; the fifth the longest; _tarsi_ shorter; _toes_ more lengthened; lateral toes nearly even; _claws_ much sharper and more curved.