The wall-cases contain mounted specimens of all the principal genera, placed in systematic order, beginning with the Crows and Birds of Paradise on the left hand on entering, and ending with the Ostriches, Emus, etc., on the right. [Illustration: BRITISH MUSEUM (NATURAL HISTORY) Ground Floor.] [Illustration: FIG. 15.--THE GREAT AUK OR GARE-FOWL (_Plautus_, or _Alca_, _impennis_), AND ITS EGG.] Among the multitude of species exhibited in this gallery, which form, however, but a small proportion of the different kinds of Birds known to inhabit the globe, only a few of the more striking can be mentioned. The various types of the Birds-of-Prey are very fully represented: from the Condor of the Andes, the large Sea-Eagle of Bering Strait, and the Great Eagle-Owl of Europe (all of which are placed in separate cases), to the Dwarf Falcon in case 53, which is not much larger than a sparrow, and preys upon insects. Among the large group of Perching-Birds, attention may be directed to the cases of Birds of Paradise and Bower-Birds in the first bay on the left. In separate cases in the sixth bay on the opposite side of the gallery are placed skeletons of the Dodo and Solitaire, large Pigeon-like birds with wings too small for flight, once inhabiting the islands of Mauritius and Rodriguez, respectively, but now extinct. Other cases on the right-hand side of the gallery are occupied by the Game-Birds, and the Wading and Swimming Birds. Here may be noticed a nearly complete series of the genera of Pheasants and Pigeons, showing the various forms. Special attention may be directed to the Great Auk (fig. 15), from the Northern Atlantic, which became extinct only in the last century. Casts of the eggs (fig. 16) of this curious bird are also exhibited. A case in the 7th bay contains a series of Penguins, flightless birds which may be regarded as representing the northern Auks and Guillemots in the southern oceans. Particularly interesting is the great Emperor Penguin, which lays its eggs and rears its young in winter amidst the ice of the Antarctic. Most of the specimens exhibited were obtained during the British Antarctic Expedition of 1839–43, under the command of Captain Sir James Clark Ross. Other noteworthy types are the Great Bustard, once an inhabitant of England, and the Flamingos; a pair of the latter being exhibited with their nest. In the first two bays on the right side of the gallery are placed specimens of the Ostrich group, characterised by the flat or raft-like form of the breast-bone. Owing to the rudimentary character of their wings, these Birds lack the power of flight. They include the largest existing Birds, the Ostriches, Emus, and Cassowaries, as well as the small Kiwis (_Apteryx_) of New Zealand, together with the extinct Moas (_Dinornis_, etc.), of the same country, and the Roc (_Æpyornis_) of Madagascar. A fossil egg of the latter is placed alongside eggs of the existing species of the group.