CHAP. XIX THE MADAGASCAR GROUP 



428 



The Mascarene Islands} — In the Geographical Bistri- 

 hutio7i of Animals, a summary is given of all that was 

 known of the zoology of the various islands near 

 Madagascar, which to some extent partake of its peculiari- 

 ties, and with it form the Malagasy sub-region of the 

 Ethiopian region. As no great additions have since been 

 made to our knowledge of the fauna of these islands, and 

 my object in this volume being more especially to 

 illustrate the mode of solving distributional problems by 

 means of the most suitable examples, I shall now confine 

 myself to pointing out how far the facts presented by these 

 outlying islands support the views already enunciated with 

 regard to the origin of the Madagascar fauna. 



The Comoro Islands. — This group of islands is situated 

 nearly midway between the northern extremity of 

 Madagascar and the coast of Africa. The four chief 

 islands vary between sixteen and forty miles in length, the 

 largest being 180 miles from the coast of Africa, while one 

 or two smaller islets are less than 100 miles from 

 Madagascar. All are volcanic. Great Comoro being an 

 active volcano 8,500 feet high; and, as already stated, they 

 are situated on a submarine bank with less than 500 

 fathoms soundings, connecting Madagascar with Africa. 

 There is reason to believe, however, that these islands are 

 of comparatively recent origin, and that the bank has been 

 formed by matter ejected by the volcanoes or by upheaval. 

 Anyhow, there is no indication whatever of there having 

 been here a land-connection between Madagascar and 

 Africa ; while the islands themselves have been mainly 

 colonised from Madagascar, some of them making a near ap- 

 proach to the 100-fathom bank which surrounds that island. 



The Comoros contain two land mammals, a lemur and a 

 civet, both of Madagascar genera and the latter an 

 identical species, and there is also a peculiar species of 

 fruit-bat {Pteropus comorensis), a group which ranges from 

 Australia to Asia and Madagascar but is unknown in 

 Africa. Of land-birds forty-one species are known, of 



^ The term "Mascarene" is used here in an extended sense, to include 

 all the islands near Madagascar which most nearly resemble it in their 

 animal and vegetable productions. 



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