The geographical distribution of animals, with a study of the relations ...

—;280 ZOOLOGICAL GEOGRAPHY. [part hi.Africa by the single genus Agama, have here three peculiargenera, Trachcloptychus, Chalarodon, and Hoplurus. Lastly, theAmerican Iguanidse are said to be represented by a species of theSouth American genus Opiums. The classification of Reptilesis in such an unsettled state that some of these determinationsof affinities are probably erroneous ; but it is not likely thatany corrections which may be required will materially affect thegeneral bearing of the evidence, as indicating a remarkableamount of Oriental and American relationship.The other groups are of less interest. Tortoises are representedby two African or wide-spread genera of Testudinidee,Teshido and Chersina, and by one peculiar genus, Pyxis ; andthere are also two African genera of Chelydidae.The Amphibia are not very well known. They appear to beconfined to species of the wide-spread Ethiopian and Orientalgenera Hylarana, Polypedates, and Rappia (Polypedatidse)and Pyxicephahcs (Ranidse).Frcsh-ivater Fishes.—These appear to be at present almostunknown. When carefully collected they will no doubt furnishsome important facts.TJie Mascarene Islands.The various islands which surround Madagascar—Bourbon,Mauritius, Rodriguez, the Seychelles, and the Comoro Islands—all partake in a considerable degree of its peculiar fauna,while having some special features of their own.Indigenous Mammalia (except bats) are probably absent fromall these islands (except the Comoros), although Lemur and Centetesare given as natives of Bourbon and Mauritius. They have,however, perhaps been introduced from Madagascar. Lemurmayottensis, a peculiar species, is found in the Comoro Islands,where a Madagascar species of Viverra also occurs.Bourbon and Mauritius may be taken together, as they muchresemble each other. They each possess species of a peculiargenus of Campephagidse, or caterpillar shrikes, Oxynotus; whilethe remarkable Fregilupus, belonging to the starling family,inhabits Bourbon, if it is not now extinct. They also have