NEOTROPICAL REGION.] must be remembered too that where, in the preceding paragraphs, " lines " of demarcation have been spoken of, such lines are in truth tracts of country often from one to two hundred miles in breadth, and in most cases there is no hope that the boundaries will ever attain any great degree of precision. Some advance of knowledge in this direction will no doubt accrue as the elevation and contour of hills and table-lands become more accurately laid down ; but at first the effect of this increase to our information will certainly be to complicate matters, by shewing the existence within one Subregion of spurs, isolated spots, or enclosed areas belonging to another, and as yet unsuspected. Still the amount of light thrown on the Neotropical Region by the persevering labours of the eminent ornithologists before named, seems to deserve being brought to a focus ; and accordingly the following summary is now offered in the hope that some of the characteristics of the avifauna of the Region may thereby be more readily comprehended. Of the families of Birds peculiar to the Neotropical Region twenty-four in number, according to Messrs Sclater and Silvin the distribution may be tabulated as follows : Subregion. Peculiar to 1 Sub- region. Common to 2 Sub- regions. Common to 3 Sub- regions. Common to 4 Sub- regions. Common to 5 Sub- regions. Common to all Sub- regions. Patagonian I 1 3 1 1 3
Brazilian 4 1 8 5
Amazonian 1
1 8 5
Subandcan 1 1 2 8 5
Central-American
1 1 7 5
Antillean .. 1
2
This table will serve to shew the close alliance of the four middle Subregions to one another in their most remarkable forms, and, at the same time, the singularity displayed by the Patagonian and Antillean Subregions ; while it will also make evident that no family peculiar to the Region is found in all its Subregions. mian (1.) The Patagonian Subregion, lying chiefly at the >i n - southern extremity of the continent, seems to present the greatest affinity to that in which the Australian avifauna reaches its climax. This is shewn not only by the pre valence in it, alone of all the Neotropical Subregions, of the Ratitce, which wander over its solitudes, and the Penguins (Spheniscidce), which haunt its shores ; but by the low, generalized, and peculiar forms like Thinocorus and Attagis among the widely- varying Limicolce, and the Pteroptochidce ^though some few species of this family occur elsewhere in South America) among the Passeres. The family of Plantcutters (Phytotomidce) is almost peculiar, only just intruding upon Southern Brazil. Of the more characteristic families of Birds of the New World, some 3 only (Dendroco laptidce, Formicariidai, and Trochilidae} shew themselves in any great abundance, while but 2 others, which are feebly represented, occur within the ill-defined limits of its southern province, Patagonia, the rest of its terrestrial, and still more of its littoral or maritime, avifauna consist ing of families, or groups of families, which are nearly cosmopolitan. On the pampas of La Plata we find the number of characteristic Neotropical forms much increased, but still the poverty of the Argentine ornis is of the most marked kind when compared with the wealth of the more fertile tracts which lie on its northern and eastern frontiers. In La Plata we have but 2 other familes (Tyrannidce and Palamedeidce] coming under this category that are at all well developed. Mniotiltidce, Vireonidce, and Ccerebidce do not appear at all, and Tanagridae but in small numbers. As has been said already, the Subregion extends northward aloug the chain of the Andes, and with this extension it 1 The Thinocoridce may be questioned as having a real existence. The writer would be inclined to include it in the cosmopolitan family of Charadriidce. 745 seems proper to take in their arid and barren western slopes as well as a portion of the tract lying between that range and the sea, so as to include Chile and a considerable slice of Peru. But even by so doing we gain but little. No more of the characteristically Neotropical forms mount these lofty ascents in any multitude, nor are we able to add any forms of very wide distribution. However, through out the whole Subregion many genera, and species with out number, which are absolutely peculiar, occur, and thus aid in stamping the quality of the tract. Indeed, the very presence of the Struthious family Rheidce, with its two or three species, would serve alone to do this ; and as its head quarters are in Patagonia, that country becomes of sufficient importance to give its name to the Subregion of which it forms at most but a moiety. Entering more into details, we find the Patagonian Sub- Peculiai region possessing about 46 genera of birds not found else- genera. where in South America. Of these 30 are strictly Land- birds 3 belonging to the family Eniberizidce, 1 to Icteridce, 5 to Tyrannida;, 8 to Dendrocolaptidce, 4 to Pteroptochidce, 3 to Trochilidce, 1 to Psittacid<%, 1 to Falconidce, 1 to Columbidce, 2 to Tinamidce, and 1 to Jfheidce. Of the rest there are 3 genera of Charadriidce (as restricted), 1 of which (Eudromias) is doubtfully identical with a genus of the Old World; 2 genera of the peculiar family Thinoco- ridce; Chionis, an antarctic form ; 2 genera of Scolopacidce, one peculiar, the other (Rhynehcea) rather widely spread over Australia, India, and Africa ; 2 genera of Anatidce, both peculiar ; 2 genera of Laridce, one peculiar, the other belonging to subpolar seas ; 1 genus of the cosmopolitan Podicipedidoe ; and 3 genera of Spheniscidce, a family limited to the Antarctic or Subantarctic Ocean. But further into particulars want of space forbids our going, save to remark on a very peculiar and instructive case offered by Eustephanus, a genus of Trochilidce. Of this Hummi section of Humming-birds there are three known species one, E. galeritus, found in Chile, evidently its mother- country, but also occurring from 400 to 600 miles from the mainland on both of the chief islets of the little Juan Fernandez group Masatierra and Masafuera ; but each of these limited spots has besides its own peculiar species of the genus the former E. fernandensis and the latter E. ley- boldi. This alone would present nothing at all unparalleled elsewhere ; but it is curious that while both sexes of the more widely-ranging E. galerilus have a green plumage, the males of the other two have a brilliant red colour, and generally resemble each other, though the females of each differ more decidedly. Supposing, as we may justly do, that all these species have descended from a common ancestor, Mr Sclater has shewn 2 the probability that E. galeritus represents the appearance of the parental stock that in bygone times colonized the Juan-Fernandez cluster, of which E. fernandensis, now peculiar to Masa tierra, and the most aberrant from the original form, is the progeny of the earliest settlers, and E. leyboldi, confined to Masafuera, is the descendant of a later immigration, while, still more recently, E. galeritus has found its way to both islets, and in each yet possesses its normal characters. Passing over, as not affording anything especially remark able, the chain of islands, from Chiloe to Cape Horn, in which the range of the Andes plunges into the Southern Ocean, though alongside of it lie Tierra del Fuego and its satellites, which form an important adjunct to the South- American continent, our attention is turned to the Falk- Birds o lands, an interesting and considerable group of islands Falklan situated over 200 miles to the north-east of the historic Ts Strait of Lemaire. Here we find 1 8 species of Land-birds 7 belonging to the order Accipitres and 11 to Passeres. Of z Ibis, 1871, pp. 180-183.
in. 94