REPTILES— FISHES AND INVERTEBRATES 199 



the muzzle. The dwarf chamseleons of the genus Brookesia, one of which is not 

 more than 3 inches in length, are peculiar to the island. 



Geckos of various kinds occur in the island, as they do throughout the tropical 

 and subtropical zone of the globe. Among these, the most remarkable is the bark- 

 gecko (Uroplates Jimbriatus), which represents a generic type peculiar to the 

 islands, and takes its English name from the resemblance of the mottled black- 

 and-white skin to the lichen-clad bark of the trees on which it dwells. The tail 

 is short and trowel-like, and the blood-red eye unusually large. The Old World 

 families of agama lizards (Agamidw), monitors (Varanidce), and typical lizards 

 {Lacertidce) are, however, absent. On the other hand, Ethiopian affinities are 

 again exhibited by the occurrence of the typical genus of lizards of the family 

 Gerrhosauridce, which are otherwise exclusively African. Of the great family 

 of scinks (Scincidce), there are several Malagasy representatives. 



Amphibians are represented, and that but poorly, by certain frogs of the 

 typical family Ranidce, which are mainly of African affinities. There are, for 

 example, a few species of the genus Arthroleptis, the other members of which are 

 restricted to Africa and the islands of the Indian Ocean ; while the peculiar 

 Malagasy genus Mantella appears to be related to the Ethiopian Bendrobates. 

 Toads (Bufonidce) and true tree-frogs (Hylidce), as well as the limbless coecilians 

 (Cceciliidce), are entirely lacking. 



Fishes and Information with regard to the fresh-water fishes of Madagascar 



invertebrates. j s s t.ill very incomplete. In addition to certain gobies and species of 

 Bules, which are not truly fresh-water types, a few representatives of the 

 Chromidce, a family common to South America and Ethiopian Africa, are known. 



Regarding its land-snails, the island differs very notably from Africa south 

 of the Sahara. The latter area, as stated in the preceding chapter, is characterised 

 by its poverty in snails of the Helix group and of the operculated family Cyclo- 

 stomatidce. Madagascar, on the other hand, forms the headquarters of the genus 

 Cyclostoma, of which it possesses more than fifty species ; the genus also occurs 

 in the Seychelles, the Comoros, and Mauritius. The Helix group is well repre- 

 sented, the two peculiar generic, or subgeneric, types Helicophanta and Ampelita, 

 which are unknown in the islands just mentioned, containing remarkably large 

 and handsome species. Of these, Helicophanta souverbiana has a large shell of 

 a rich brown colour, measuring about 3 inches across, and distinguished by 

 the unusually large size of its embryonic portion, which forms the summit of the 

 flattened spiral. The agate-snails (Achatina), so numerous in Africa, are scarce, 

 and the Ethiopian genera Pachnodus and Rachis, belonging to the Bulimus group, 

 are represented only by two species. In the same group the presence of a species 

 of the otherwise exclusively Oriental genus Kaliella, which has been regarded as 

 inseparable from one of the Indian forms, is very remarkable. This Indian 

 affinity, which is paralleled in the case of the flying-foxes of the genus Pteropus, 

 is further borne out by the occurrence in the rivers of Madagascar of species of 

 Paludomus, a genus essentially Oriental, with a few representatives in the 

 Seychelles and Somaliland. Melanatria, again, is an exclusively Malagasy type, 

 with relationships to certain Sinhalese and Indian snails. Moreover, some of 

 the Malagasy species of Melania, characterised by the elongated spiral of the 



