272 
ZOOLOGICAL GEOGRAPH Y. 
[part III. 
The only known land-shells are 2 peculiar species of Balea, a 
genus only found elsewhere in Europe and Brazil. 
IV. Madagascar and the Mascarene Islands , or the Malagasy 
Sub- region. 
This insular sub-region is one of the most remarkable zoo- 
logical districts on the globe, bearing a similar relation to Africa 
as the Antilles to tropical America, or New Zealand to Australia, 
but possessing a much richer fauna than either of these, and in 
some respects a more remarkable one even than New Zealand. 
It comprises, besides Madagascar, the islands of Mauritius, 
Bourbon, and Rodriguez, the Seychelles and Comoro islands. 
Madagascar itself is an island of the first class, being a thousand 
miles long and about 250 miles in average width. It lies 
parallel to the coast of Africa, near the southern tropic, and is 
separated by 230 miles of sea from the nearest part of the con- 
tinent, although a bank of soundings projecting from its western 
coast reduces this distance to about 160 miles. Madagascar is 
a mountainous island, and the greater part of the interior consists 
of open elevated plateaus ; but bet ween these and the coast there 
intervene broad belts of luxuriant tropical forests. It is this 
forest-district which has yielded most of those remarkable types 
of animal life which we shall have to enumerate; and it is 
probable that many more remain to be discovered. As all the 
main features of this sub-region are developed in Madagascar, 
we shall first endeavour to give a complete outline of the fauna 
of that country, and afterwards show how far the surrounding 
islands partake of its peculiarities. 
Mammalia. — The fauna of Madagascar is tolerably rich in 
genera and species of mammalia, although these belong to a very 
limited number of families and orders. It is especially charac- 
terized by its abundance of Lemuridse and Insectivora ; it also 
possesses a few peculiar Carnivora of small size ; but most of 
the other groups in which Africa is especially rich — apes and 
monkeys, 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 
