(3) =The Malagasy Sub-region= includes Madagascar with its attendant satellites Bourbon, Mauritius, and Rodriguez, 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_, _Gibbus_), the occurrence of a considerable number of true Helicidae of great size and beauty, and the prominence of the genus _Cyclostoma_. (_a_) _The Madagascan Province._--The land Mollusca of Madagascar, although as yet imperfectly known, possess a striking individuality. Two of the chief characteristics of the Ethiopian region are the paucity of its land operculate and of its _Helix_ fauna; Madagascar is especially distinguished by the rich development of both these groups. For size, colouring, and beauty of shape, the Helicidae of the two sub-genera _Ampelita_ and _Helicophanta_ rival, if they do not surpass, any in the world. They are quite peculiar to this sub-region, not a trace of them occurring on the Mascarenes, Seychelles, or even on the Comoros. _Helicophanta_ is distinguished by the enormous size of its embryonic 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 _Bulimini_ (_Pachnodus_ and _Rachis_) are represented by two species, but _Achatina_, so abundant on the mainland, is scarce. Two other groups of _Buliminus_, _Leucotaenia_ and _Clavator_, are peculiar. The presence of a single _Kaliella_, specifically identical with a common Indian form, is very remarkable. _Cyclostoma_ 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 Helicidae, this genus is not restricted to Madagascar; several species occur on the mainland, 6 on the Comoros, one on the Seychelles, and 16 in Mauritius. The sub-genera _Acroptychia_ and _Hainesia_ are peculiar. [Illustration: FIG. 222.--_Pachyotus auris vulpina_ Desh., St. Helena (sub-fossil).] [Illustration: FIG. 223.--_Helix_ (_Helicophanta_) _Souverbiana_ Fisch., Madagascar, showing embryonic shell. × ⅔.] [Illustration: FIG. 224.--_Cyclostoma campanulatum_ Pfr., Madagascar.]