We now arrive at the fifth or fissirostral division of the Psittacidae, which, by Mr Swainson, has been designated by the name of Platycercina (Broad-tail), the members of the genus Platycercus of Vigors and Horsfield being considered as its typical representatives. Of the other groups which belong to this section, we only venture to speak with diffidence, not having had an opportunity, as well from want of time as of materials, to make that strict analysis of the species which is required to trace out with certainty the true affinities, and exact station of each. We have sufficient data, however, to believe, that the ground Parrakeets (gen. Pezoporus, Illig.), the beautiful miniature Maccaw-looking species belonging to the genus Nanodes, Vigors, the two species composing Wagler's genus Nymphicus, represented by the Psitt. sisetis and Psitt. Novas Hollandiae of authors, and some other forms, among which, perhaps, the Psittacus Platurus of Tem-minck's "Planches Colories" may be included, enter into it. Those interesting species which inhabit Madagascar, and known by the name of Vasas, viz. Psitt. niger and Psitt, mascarinus, Linn., forming Wagler's genus Coracopsis, also shew a decided affinity in form and habit to the true Platycerci, and there is little doubt belong to the division. To the genus Palaernis, Vigors, which we have placed among the Macrocercinae, or Maccaw section, an approach is shewn in several species. Thus, it is strongly indicated by the resemblance the Paloeor, Barrabandi, an Australian species, which stands upon the confines of the group, bears to some of the less typical Broad-tails, in which that member in part loses its broad and depressed form. It is also visible in the wings and tail of that lovely species, the Nanodes discolor, in which the second, third, and fourth quills lose the distinct emargination of the outer web, and the two middle tail-feathers assume, in a great measure, the shape of those peculiar to the Ring-Parrakeets. The connection of the present with the preceding subfamily is supported by some of the Lories, in which the bill is comparatively strong, and the tongue loses in part its peculiar structure, and its approach to the short and even-tailed Parrots is shewn in the wide and slightly graduated tail of Platycercus sca-pulatus, as well as in the Madagascar species Psitt. niger and mascarinus. The members of this family are distinguished from the rest of the Psitta-cidae, by their slender and elevated tarsi, and the less falcated form of their claws. Their wings also are shorter, and rounded, the first quill-feather being inferior to some of the succeeding ones. In consequence of this formation, their habits are less strictly scansorial than those of the typical Parrots; but the deficiency is amply compensated by the ease and agility with which they move upon the ground, where their actions partake in a great measure of that freedom which distinguishes so many of the scansorial order, but which is almost denied to the typical Parrots, whose movements upon a plain surface are to a great degree awkward, and constrained. This formation is carried to the greatest extent in the genus Pezoporus, Illiger (Ground Parrot), in which the tarsi and toes are long and slender, and the claws nearly straight, indicating those terrestrial habits from which it has derived its name. The Platycercinae are birds of elegant and graceful form, and their carriage and actions are in accordance with it, as they display an activity and liveliness of mo tion far superior to that of the true scansorial species, and more in character with that of other birds. In richness and diversity of plumage, also, they yield to none of the tribe, whether we admire it in the varied hues of the genus Platycercus, or in those smaller species belonging to the genus Nanodes, Vigors, which have aptly been termed miniature Maccaws. Most of the members of this division also shew a decrease in the power of flight, their wings being short and rounded, as indicated by the relative length of the quill-feathers. Not having a figure illustrative of the Madagascar species, which must be considered an interesting form in this divi sion, we commence with the genus Platycercus, Vigors and Horsfield. The characters are: - Bill rather short, deeper than long, the upper mandible with the culmen indistinct, broad and rounded, bulging on the sides, the tomia with a strong emar-gination or tooth, the under mandible short, very convex, deeply emarginate, with the tip broad, short, and quadrate. Palatial cutters large, and fully developed. Tongue simple, smooth. Wings of mean length, rounded, the first quill considerably shorter than the second and third, which are the longest, and nearly equal, the second, third, fourth, and fifth with their external webs abruptly emarginated a little behind the middle. Tail broad and depressed, rounded or subgraduate, the feathers with their tips rounded. Feet with the tarsi elevated and slender. Toes slender, claws rather long and slightly falcated. The species belonging to this beautiful genus are already very numerous, and additions are constantly being made to it, as our knowledge of New Holland is extended, of which interesting country the majority of those already discovered are natives. They are of active habits, and are usually seen in large flocks, except during the period of reproduction. They feed upon seeds, particularly upon the grasses and Cerealea, and frequently do much damage in recent settlements to the ripening as well as to the new sown maize and wheat. The first species we have to notice is considered by Mr Vigors as the type of the genus: it is the Pennantian Broad-Tail.