THE ETHIOPIAN REGION" 85 



therefore, the line of the tropic of Cancer, adopted by 

 Wallace, seems to be a fairly suitable boundary. 



Besides the island of Madagascar and its appendages, 

 which contain one of the richest and most interesting of 

 all known Insular Faunas, and form a very important 

 Sub-region, which will be considered in greater detail 

 below, the Ethiopian Region possesses other islands. 

 These, however, are mostly Oceanic, and not of any 

 great importance. 



The Azores, Madeira, Canaries, and Cape Verde groups, 

 although geographically African, seem to have derived 

 their animals chiefly from Europe. They therefore belong 

 to the Palsearctic Region, and will be dealt with under 

 that head. 



The islands of St. Helena and Ascension, situated in 

 the South Atlantic, are both of them of volcanic origin, 

 and separated from the mainland of Africa by more than 

 800 miles of deep water. Neither of these islands possesses 

 any Vertebrates. The only land-groups well represented in 

 them are the Beetles and the Land-shells — a study of which 

 shows that the affinities of these islands are to Southern 

 Europe and Southern Africa, but that the Fauna is in all 

 probability an exceedingly ancient one ; since its pecu- 

 liarities are very great, and opportunities of migration 

 of new forms to these islands have been few and far 

 between. 



The other islands in the Atlantic connected with Africa 

 are Fernando Po, Prince's Island, St. Thomas, and Anno 

 Bon, all situated in the Gulf of Guinea at various distances 

 from its head. Fernando Po, an island of some 40 miles 

 in length, but separated from the mainland by a some- 

 what shallow sea about 20 miles across is said to be 



