The “pavilion” at the west end of the Bird-gallery is devoted to the exhibition of the land and fresh-water Vertebrated Animals of the British Islands. The larger Mammals and Fishes occupy the wall-case on the north side, which is surmounted with horns. In the two pairs of centre cases is exhibited the series of British Birds, supplemented by the groups, to which reference has been made already. The wall-case on the north side of the archway contains a group of Gannets and other sea-birds from the Bass Rock in the Firth of Forth. On the opposite side are two striking groups with the surroundings true to nature, the one of the Golden Eagle and the other of the Buzzard, both taken in Scotland. Other groups in the pavilion display the Kestrel, the Peregrine Falcon, and the Merlin amid natural surroundings. Among the Mammals, especial attention may be directed to a case of British Hares and Rabbits. In another case may be seen a female Badger and her young; in a third is a group of Otters; in a fourth a vixen Fox with her cubs; in a fifth a Mole-hill with its inhabitants; in a sixth a pair of Martens; in a seventh Polecats and their young; while other cases are devoted to Stoats, Weasels, Hedgehogs, Squirrels, Rats, Mice, etc. Here it may be mentioned that the animal inhabitants of any country or district are collectively termed its “_fauna_.” The British Islands in this respect belong to the great zoological region called Palæarctic, or Eastern Holarctic, embracing all Europe, the north of Africa, and the western and northern portions of Asia. As in the case of other islands, the species belonging to groups in which the power of locomotion is limited to land or fresh-water are not numerous compared with those inhabiting large continental tracts. Their numbers can only increase under exceptional circumstances, and have a tendency to diminish as the growth of human population and increase of the area of cultivated land gradually reduce their native haunts. In this way the Brown Bear, the Wolf, the Beaver, and the Wild Boar have disappeared from Britain within the historic period, while other species, such as the Badger, Marten, and Wild Cat, with difficulty maintain a more or less precarious existence. All these were originally derived from the mainland of Europe, probably before the formation of the channel which now separates it from Great Britain. The wider and older channel which separates Ireland from Great Britain has been a greater barrier to the emigration of animal life than that between the latter and the Continent, many species (as the Polecat, Wild Cat, Mole, Squirrel, Dormouse, Harvest-Mouse, Water-Rat, Short-tailed Field-Mouse, Brown Hare, Roedeer, as well as Snakes and Toads) never having crossed what is now the Irish Sea, unless by human agency.