AFRICAN REGION. 231 



with 29. There is not, therefore, that great preponderance 

 of the two first families over the remaining, which we 

 noticed in the Indian region ; in Africa there is a compara- 

 tively greater variety of distinct Freshwater types, imparting 

 to the study of its fauna an imflagging pleasure such as is 

 scarcely gained by the study of the other region. With the 

 forms peculiar to it there are combined those of India as 

 well as South America. 



In Tropical Africa there are stiU remnants of Ganoids : 

 Protopterus (Lcpidosiren) annedcns and Polypterus hicliir, with 

 tlie singularly modified Calamoichthys. The two former 

 range from east to west, and are accompanied by an Osteo- 

 glossoid {Heterotis) which has hitherto been found in the Nile 

 and on the West Coast only. 



Autochthont and limited to this region are the Mormy- 

 ridce, Fantodontidce, and Kneriidce, a singular type, somewhat 

 akin to the Loaches. Of Siluroid genera the most character- 

 istic are Synodontis, Bhinoglanis, and the electric Mcdap- 

 terurus ; of Characinoids, Citharinus, Alestes, Xciiocharax, 

 Hydrocyon, Distichodon, Ichtliyhorus. 



The regions witli which Africa (like India) has least 

 similarity are, again, the North American and Antarctic. 

 Its af&nity with the Europo-Asiatic region consists only in 

 having received, like this latter, a branch of the Cyprinoids, 

 the African Carps and Barbels resembling, on the whole, 

 more Indian than Europo-Asiatic forms. Its similarity to 

 Australia is limited to the two regions possessing Dipnoous 

 and Osteoglossoid types. But its relations to the two other 

 regions of the equatorial zone are near and of great interest. 



1. Africa has, in common with India, the Siluroid group 

 of Clariina, the Silurina, and Bagrina ; and more especially 

 the small but very natural family of Notopteridm, represented 

 by three species in India, and by two on the imsf, coast of 

 Africa. It would be hazardous to state at present in which 



