Page:Encyclopædia Britannica, Ninth Edition, v. 3.djvu/765

Rh NEOTROPICAL REGION.] 38 (!) to Trochilidce, 1 to the peculiar family Steatormth. idee, and 1 to Picidce, Strigidce, and Craddce respectively - The enormous differential development of the peculiarly New-World family Trochilidce calls for some remark, and is only approached (as will presently be seen) by that which has occurred in Central America. The habitat of some of these forms of Humming-birds, whether genera or species and the latter are wonderfully numerous is extremely restricted. That of Loddigesia mirabilis, long since de scribed from a still unique specimen in the Loddiges col lection, is Chachapoyas in northern Peru, and though pos sibly more pains has been taken to discover it and compass the capture of other examples than has been the case with any other Bird, it has not been again met with. Its haunts may, therefore, be safely presumed to be especially confined. Two species of Oreotrochilus (0. chimborazo and 0. picldn- chce) have their abode almost limited to the slopes of the lofty mountains whence they take their name, and nearly as much may be said of others. The Tanagers (Tana- gridae) birds of varied form, and generally of exquisite plumage- also frequent this Subregion in great force, and among them there is here found, perhaps, the greatest amount of differentiation, both generic and specific. Of the hundreds of other curious ornithological charac teristics of the Subregion which might easily be cited, no more can here be given, but a brief notice of the avifauna I of its extreme points seems to be required. It has now been for some time fully admitted by all competent authorities that the islands of Trinidad and Tobago, which the geo grapher might be inclined to class with the xlntillean chain, must be regarded as being truly portions of the South- American continent, detached in comparatively recent times, and even now only separated from Venezuela by a compa ratively shallow sea. Neither of these islands has a single peculiar species, 1 and except, perhaps, some stragglers from the north, not one which is not also found on the nearest mainland, though, of course, many inhabitants of the neigh bouring continent do not pass either the Dragon s or the Serpent s Mouth, as the two narrow channels which cut off Trinidad from South America are called. We may presume that the various islands, Margarita, Curacao, and Oruba, which Ke off the northern coast of Venezuela, also belong to this Subregion, though scarcely anything is known of their animal products. Very different from this state of things is that which obtains at the opposite extremity of the Subregion. The pagos present not merely a large number of peculiar species, but 4 peculiar genera of Land-birds ; 1 of these, Certhidea, belongs to the Coerebidce, and the other 3, Geospiza, Ca- marhynckus, and Cadomis, seem to come into the family mberizidce. 2 It was Mr Darwin who first drew attention 1 Trinidad lias about 350 species one of them (Psittacula cingu- lata) was thought to be peculiar, but Mr Salvin informs the writer that it has lately been procured in Guiana. The nearest approach, perhaps, to peculiarity is in a Thrush, which was originally described as being specifically distinct, under the name of Turdus xanthoscelus, but its claims to that consideration are now disallowed. 3 A very considerable amount of uncertainty, which at present can not be removed, though it produces some confusion, appertains to the right position of many of the New- World forms of so-called Buntings (Emberizidce) and Finches (Fringillidce). The writer is fully inclined to believe that the distinctness of these two families, which among forms of the Old &quot;World has long been recognized, and that almost without difficulty, can be fairly established, since it seems to rest on good osteological characters ; but the American genera have not yet been sufficiently examined to allow of many of them being allotted without much doubt. This uncertainty will most likely in time be removed, unless and such a probability cannot be denied some of the New-World forms turn out to be so much generalized as to fill up the gap which now presents itself between the two groups as observed in the Old World. Meanwhile, the consequent inconvenience is un avoidable. 747 to the remarkable ornis of this archipelago, and here it was, as he has told us, that there dawned upon him from its consideration that theory of &quot;Natural Selection&quot; Avhich has transformed the whole aspect of biology, and, whether wholly or partially accepted, has placed the science upon a - new and higher pedestal. Later researches, indeed, have shown the nonexistence of some of the peculiarities which this eminent observer believed, on what was then good evidence, he had determined ; but these refer to the re stricted distribution of several of the species among the different islands, and are not of any such importance as to affect his general results, while doubtless, had his visit to this &quot; little world within itself,&quot; as he appropriately calls it, been of longer duration, he would have become aware of these minor facts. The strictly-speaking Land-birds of the Galapagos seem to be some 30 in number, of which about 26 are Passeres. Among these, 1 only, Dolichonyx oryzivorus (belonging to the family Icteridce), and obviously a straggler, is identical with a species of the mainland, while 2, a Dendroeca (Mniotiltidce), and a Progne (Hirundinidce], have been by some considered to be distinct species, by others but local races, which means, of course, that from one cause or another isolation has not yet modified them . so as to depart greatly from their congeneric continental forms, but the remaining 23 (?) are peculiar, and, what is especially worthy of notice, no fewer than 18 (f), or nearly three-fourths of the whole number, belong to the four peculiar genera. There is also a peculiar species of Buzzard, agreeing closely in every habit and even in tone of voice with the carrion-eating Polybori, and originally described as the type of a distinct genus under the name of Cradrex galapagoensis. Apparently, too, there is a distinct and peculiar Barn-Owl (Aluco punctatissimus), but alongside of it we have the widely-spread Short-eared Owl (Asio accipitrinus), though examples of this last are said to present in these islands sufficient difference to justify the bestowal upon them of a distinct specific name. Among Water-birds, the Rallidae and Ardeidae furnish, the former one and the latter two, species not known elsewhere. A remarkable fact, also, is the asserted existence of a peculiar species of Flamingo (PJuxnicopterus glyphorhynckus ), seeing that most of the birds of this genus have a very extended distribution. A Penguin also (Spheniscus mendiculus) is at present only known from the Galapagos ; but consider ing the range of other forms of this family (Spheniscidce), we should, perhaps, be premature in as yet pronouncing it a peculiar species, though the existence of a Penguin at all under the equator raises a presumption that such may be the case. There is, however, one feature in the avi- Their Sul fauna of these islands which should not be overlooked, regional Notwithstanding that the Galapagos are here placed as forming an outlying portion of the Subandean Subregion, the fact must not be concealed that their ornis seems to have no very special or intimate relation thereto. All that can be averred of it is that it is American. In the sub- region just named, as has been above shown, the Trochi lidce attain their maximum of development, yet no Hum ming-birds are found in this archipelago. So also with the Tanqgridce, of which there are abundant Subandean repre sentatives, the Dendrocolaptidce, Formicariidce, and other characteristic Neotropical families. In the Galapagos none of them are found. It is true that the presence of a species of the South-American genus PyrocepJialus, and of a genus of the Neotropical family Ccerebidce, may be a set off on the other side ; but on the whole, it seems quite likely that the relations of this isolated, equatorial province (for so it is entitled to be deemed) are as near to the north as to the south, if not nearer, and it is quite possible that, having its ornithological characters only in view, future zoogeographers may think fit to ally it to the former rather
 * os. interesting group of volcanic islands known as the Gala