MADAGASCAR 335 



time much more widely distributed. Endodonta (an essentially 

 insular form, like Om^yJudotropis) actually occurs on Fernando 

 Noronha, off the Brazil coast, and we shall see how an Indian 

 and even a Polynesian element is present off the eastern coasts 

 of Africa. 



Ascension I. — One indigenous species, a so-called Limax, is all 

 that has ever been discoNcivd. 



(3) The Malagasy Sub-region includes Madagascar with its 

 attendant satellites Bourbon, Mauritius, and Eodriguez, and the 

 Seychelles and Comoro groups. No land Mollusca are known 

 from the Amirantes, the Chagos, or from Aldabra. The special 

 characteristics of the sub-region are the great development of the 

 carnivorous land Mollusca {Ennea, Gihhus), the occurrence of a 

 considerable niunber of true Helicidae of great size and beauty, 

 and the prominence of the genus Cydostoma. 



(a) The 3£adagascan Province. — The land Mollusca of Mada- 

 gascar, although as yet imperfectly known, possess a striking 

 individuality. Two of the chief characteristics of the Ethiopian 

 region are the paucity of ilis land operculate and of its Helix 

 fauna ; Madagascar is especially distinguished by the rich develop- 

 ment of both these groups. For size, colouring, and beauty of 

 shape, the Helicidae of the two subgenera Ampelita and Helico- 

 phanta rival, if they do not surpass, any in the w^orld. The^• 

 are quite peculiar to this sub-region, not a trace of them occur- 

 ring on the Mascarenes, Seychelles, or even on the Comoros. 

 Helicophanta is distinguished by the enormous size of its embry- 

 onic shell, which persists in the adult (Fig, 223), and in this 

 respect the group appears to be related to Acavus (Ceylon, Fig. 

 204) and Panda (N.E. Australia). As is usual when Helix is 

 well developed, Nanina (about 12 sp.) is proportionately scanty. 



The African Bidimini {Pachnodus and Rachis) are repre- 

 sented by tw^o species, but Achatina, so abundant on the main- 

 land, is scarce. Two otlier groups of Ptdiminus, Leucotaenia 

 and Clavator, are peculiar. The presence of a single Kaliella, 

 specifically identical with a common Indian form, is verv 

 remarkable. 



Cydostoma proper, of which Madagascar is the metropolis, 

 is richly developed (54 sp.). Many of the species are of great 

 size and of striking beauty of ornamentation. Unlike its Heli- 

 cidae, this genus is not restricted to Madagascar ; several species 



