280 ZOOLOGICAL GEOGRAPHY. [part hi. 



Africa by the single genus Agama, have here three peculiar 

 genera, Tracheloptychus, Chalarodon, and -Hoplurus. Lastly, the 

 American Iguanidse are said to be represented by a species of the 

 South American genus Opiums. The classification of Eeptiles 

 is in such an unsettled state that some of these determinations 

 of affinities are probably erroneous ; but it is not likely that 

 any corrections which may be required will materially affect the 

 general bearing of the evidence, as indicating a remarkable 

 amount of Oriental and American relationship. 



The other groups are of less interest. Tortoises are repre- 

 sented by two African or wide-spread genera of Testudinidse, 

 Testudo and Chersina, and by one peculiar genus, Pyxis ; and 

 there are also two African genera of Chelydidae. 



The Amphibia are not very well known. They appear to be 

 confined to species of the wide-spread Ethiopian and Oriental 

 genera — Hylarana, Polyp>edates, and JRappia (Polypedatidse) ; 

 and Pyxicephalus (Ranidse). 



Fresh-water Fishes. — These appear to be at present almost 

 unknown. When carefully collected they will no doubt furnish 

 some important facts. 



Tlie 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 from 

 all these islands (except the Comoros), although Lemur and Cen- 

 tetes are given as natives of Bourbon and Mauritius. They have, 

 however, perhaps been introduced from Madagascar. Lemur 

 mayottensis, 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 much 

 resemble each other. They each possess species of a peculiar 

 genus of Campephagidse, or caterpillar shrikes, Oxynotus; while 

 the remarkable Fregilupus, belonging to the starling family, 

 inhabits Bourbon, if it is not now extinct. They also have 



