Like the last group, the present is strictly confined to Australia, every one of the colonies of which country, from north to south and from east to west, is inhabited by a species peculiarly and restrictedly its own. They have many characters in common with the _Pachycephalæ_, which they also resemble in their actions, food, economy and nidification. They are neither Shrikes nor Thrushes, but are most nearly allied to the former; they are insect-feeders to a very great extent, but occasionally partake of mollusks and berries. Some of them defend themselves vigorously with both bill and claws when attacked. Their voice is a loud whistle, some parts of which are not devoid of melody, particularly the loud swelling notes. The nest is rather slightly built, round and cup-shaped in form, and is mostly placed in the hollow spout of a tree: the eggs are four in number. 119. Colluricincla harmonica Vol. II. Pl. 74. _Certhia canescens_, Lath. Gen. Hist. vol. iv. p. 180? Inhabits New South Wales. 120. Colluricincla rufiventris, _Gould_ Vol. II. Pl. 75. Inhabits Western Australia. 121. Colluricincla brunnea, _Gould_ Vol. II. Pl. 76. Inhabits Port Essington. 122. Colluricincla Selbii, _Jard._ Vol. II. Pl. 77. Inhabits Van Diemen’s Land. 123. Colluricincla parvula, _Gould_ Vol. II. Pl. 78. Inhabits the northern parts of the country. 124. Colluricincla rufogaster, _Gould_. _Colluricincla rufogaster_, Gould in Proc. of Zool. Soc., Part XIII. p. 80. I have assigned this name to a bird lately sent to me by Mr. Strange from the brushes of the Clarence in New South Wales; it may hereafter prove to be identical with the last-mentioned species, _C. parvula_, the form and admeasurements being precisely the same; but the bird from New South Wales has a lighter coloured bill, and the whole of the under surface washed with deep rufous. The locality of the bird described by me in the Proceedings of the Zoological Society, Part IV. p. 6, as _Colluricincla fusca_, being still unknown, that species has not been included. Genus FALCUNCULUS, _Vieill._ The two species of this genus are not only strictly Australian, but are confined to the southern parts of the country; the _F. frontatus_ inhabiting New South Wales and South Australia, and the _F. leucogaster_ Western Australia. When attacked by their natural enemies or by man, both species defend themselves with their powerful bill and claws with the utmost fury; they also by the same means readily tear off pieces of rotten wood and the thin scaly bark of the _Eucalypti_ in search of insects. The branches of trees are their usual place of resort, and in many of their actions and habits they closely resemble the Tits of Europe and India (genus _Parus_), while they also assimilate to the _Pachycephalæ_. They build a round, cup-shaped nest.