280 ZOOLOGICAL GEOGRAPHY. [PART III. 
Africa by the single genus Agama, have here three peculiar 
genera, T'racheloptychus, Chalarodon, and Hoplurus. Lastly, the 
American Iguanide are said to be represented by a species of the 
South American genus Oplurus. The classification of Reptiles 
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 Testudinide, 
Testudo and Chersina, and by one peculiar genus, Pyxis ; and 
there are also two African genera of Chelydide. . 
The Amphibia are not very well known. They appear to be 
confined to species of the wide-spread Ethiopian and Oriental 
genera—Hylarana, Polypedates, and Rappia (Polypedatide) ; 
and Pyxicephalus (Ranidee). 
Fresh-water Fishes—These appear to be at present almost 
unknown. When carefully collected they will no doubt furnish 
some important facts. 
The 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 Campephagide, or caterpillar shrikes, Oxynotus ; while 
the remarkable Fregilupus, belonging to the starling family, 
inhabits Bourbon, if it is not now extinct. They also have 
