336 



MADAGASCAR 



occur on the mainland, 6 on the Comoros, one on the Seychelles, 

 and 16 in Mauritius. The sub-genera Acroptychia and Hainesia 

 are peculiar. 



The fresh-water Mollusca of Madagascar contain further 



Fig. 222. — Pachyotus auris 

 vulpina Desh,, St. Helena 

 (sub-fossil). 



Fig. 223. —Helix (Helicophanta) 

 Souverbiana Fisch., Mada- 

 gascar, showing embryonic 

 shell. X a. 



traces of Indian relationship. Thus we find two species of 

 Pahidomus, a genus whose metropolis is Ceylon, India, and 

 Further India, and which is barely represented on the Seychelles 

 and in the Somali district. Melanatria, which is peculiar to 

 Madagascar, has its nearest affinities in the Cingalese and East 

 Indian faunas. Several of the Melania and the two Rithynia are 



of a type entirely wanting in Africa, 

 but common in the Indo-Malay sub- 

 region. Not a single one of the char- 

 acteristic African fresh-water bivalves 

 (^Mutela^ SpatJia, Aetheria^ Galatea, 

 etc.) has been found in Madagascar. 

 On the other hand, certain African 

 FiG.224.-Cyciostoma campanu- Gasteropoda, such as Cleopatra and Isi- 



m«Mw Pfr., Madagascar. . ,. . . ^ 



aora, occur, indicating, in common with 

 the land Mollusca, that an ultimate land connexion with Africa 

 must liave taken place, but at an immeasurably remote period. 



