The geographical distribution of animals, with a study of the relations ...

272 ZOOLOGICAL GEOGRAPHY. [part hi.The only known land-shells are 2 peculiar species of Balea, agenus only found elsewhere in Europe and Brazil.IV. Madagascar and the Mascarene Islands, or the MalagasySub-region.This insular sub-region is one of the most remarkable zoologicaldistricts on the globe, bearing a similar relation to Africaas the Antilles to tropical America, or New Zealand to Australia,but possessing a much richer fauna than either of these, and insome respects a more remarkable one even than New Zealand.It comprises, besides Madagascar, the islands of Mauritius,Bourbon, and Bodriguez, the Seychelles and Comoro islands.Madagascar itself is an island of the first class, being a thousandmiles long and about 250 miles in average width. It liesparallel to the coast of Africa, near the southern tropic, and isseparated by 230 miles of sea from the nearest part of the continent,although a bank of soundings projecting from its westerncoast reduces this distance to about 160 miles. Madagascar isa mountainous island, and the greater part of the interior consistsof open elevated plateaus ;but between these and the coast thereintervene broad belts of luxuriant tropical forests. It is thisforest-district which has yielded most of those remarkable typesof animal life which we shall have to enumerate ; and it isprobable that many more remain to be discovered. As all themain features of this sub-region are developed in Madagascar,we shall first endeavour to give a complete outline of the faunaof that country, and afterwards show how far the surroundingislands partake of its peculiarities.Mammalia.—The fauna of Madagascar is tolerably rich ingenera and species of mammalia, although these belong to a verylimited number of families and orders. It is especially characterizedby its abundance of Lemuridaa and Insectivora ;it alsopossesses a few peculiar Carnivora of small size ; but most ofthe other groups in which Africa is especially rich—apes andmonkeys, lions, leopards and hyaenas, zebras, giraffes, antelopes,elephants and rhinoceroses, and even porcupines and squirrels,are wholly wanting. No less than 40 distinct families of land