The next following order, Herodiones, is of much more importance in Argentine Ornithology, not less than 19 species of this group being already known to exist within our limits, out of a total of 44 Neotropical species. And amongst these we can pick out the little Variegated Bittern (_Ardetta involucris_) and the four species of Ibises as being highly characteristic members of the Argentine Ornis. The tenth order, that of Anseres, or Waterfowl, commonly so-called, is also largely in excess as regards the number of species. Out of a total of 64 Anseres belonging to the Neotropical Regions, 23 are met with in the Argentine Republic. Moreover, the greater number of these are exclusively Antarctic species, restricted to the Patagonian Subregion. Amongst them we may specially call attention to the Black-necked Swan (_Cygnus nigricollis_), the Chiloe Wigeon (_Mareca sibilatrix_), and the Rosy-billed Duck (_Metopiana peposaca_) as highly characteristic and ornamental species. Proceeding to the next order, that of the Pigeons (Columbæ), we find the number of Argentine species to be slightly below the average. Several fine Pigeons and Doves are well-known inhabitants of the Republic, but the Columbine order is not a prominent one within our limits. The Gallinaceous birds of the Neotropical Region are about ninety in number, the greater part of these belonging to the Curassows, Cracidæ, a family specially adapted for habitation in the extensive forests of the New World. Four species of Cracidæ have been met with in the forest-region of Northern Argentina; but the Gallinaceous group as a whole must be held to be deficient in this part of South America, the place in Nature which these birds fill in other regions being occupied here by the more lowly organized Tinamous, of which we shall speak further on. The Geranomorphæ of the Argentine Republic are much in excess as regards the number of species. This arises mainly from the abundant supply of Rails and Crakes which Nature has provided for the more swampy districts of the pampas, and to the presence of no less than three distinct species of Coots (_Fulica_), which appear to be generally abundant on the lakes and pools. Nor must we forget to mention as of special interest the two Cariamas which belong to this order, and which are the only representatives of a family of very peculiar structure. One of the two Cariamas is, so far as we know, absolutely confined to the Northern provinces of the Argentine Republic; the second is a bird of the campos of Southern Brazil, which only just comes within our limits.