CHAP. XIX.] 



THE MADAGASCAR GROUP. 



401 



are of granite, with mountains rising to 3, 000 feet in Mahe, and 

 to from 1,000 to 2,000 feet in several of the other islands. We 

 can therefore hardly doubt that they form a portion of the great 

 line of upheaval which produced the central granitic mass 

 of Madagascar, intervening points being indicated by the 

 Amirantes, the Providence, and the Farquhar Islands, which, 

 though all coralline, probably rest on a granitic basis. Deep 

 channels of more than 1,000 fathoms now separate these 

 islands from each other, and if they were ever sufficiently 

 elevated to be united, it was probably at a very remote epoch. 



The Seychelles may thus have had ample facilities for 

 receiving from Madagascar such immigrants as can pass over 

 narrow seas ; and, on the other hand, they were equally favour- 

 ably situated as regards the extensive Saya de Malha and 

 Cargados banks, which were probably once large islands, and 

 may have supported a rich insular flora and fauna of mixed 

 Mascarene and Indian type. The existing fauna and flora of 

 the Seychelles must therefore be looked upon as the remnants 

 which have survived the partial submergence of a very extensive 

 island ; and the entire absence of mammalia may be due, either 

 to this island having never been actually united to Madagascar, 

 or to its having since undergone so much submergence as to 

 have led to the extinction of such mammals as may once have 

 inhabited it. The birds and reptiles, however, though few in 

 number, are very interesting, and throw some further light on 

 the past history of the Seychelles. 



Birds of the Seychelles. — Fifteen indigenous land-birds are 

 known to inhabit the group, thirteen of which are peculiar 

 species,^ belonging to genera which occur also in Madagascar or 



1 The following is a list of these peculiar birds. (See the Ihis, for 1867, 

 p. 359; and 1879, p. 97.) 



Passeres. 



PSITTACI. 



Coracopsis harldyi, 

 Palceoimis wardi. 



COLUMB^. 



A leciorcenas pulcherrhnus, 

 Turtur ro stratus. 



ACCIPITRES. 



Tinnvnculus gracilis. 



Ellisia seychellensis. 

 Copsychus seychellarum. 

 Hypsipe tes crassiros tris. 

 Tchitrea corv'ina. 

 Nectarinia dussumieri. 

 Zosterops modesta. 



„ semiflava. 

 Foudia seychellarum. 



D D 



