Chapter II: THE EQUATORIAL ZONE.--Characterized by the development

of Siluridae.
A. Cyprinoid Division. Characterized by presence of Cyprinidae,
Mastacembelidae. Anabantidae, Ophiocephalidae.
1. Indian Region. Characterized by absence of Dipneusti,
Polypteridae, Mormyridae and Characinidae. Cobitinae
numerous.
2. African Region. Characterized by presence of Dipneusti,
Polypterid and Mormyrid; Cichlid and Characinid numerous.

B. Acyprinoid Division. Characterized by absence of Cyprinidae and the
other families mentioned above.
1. Tropical American or Neotropical Region. Characterized by
presence of Dipneusti; Cichlidae and Characinidae numerous;
Gymnotidae and Loricariidae.
2. Tropical Pacific Region. Includes the Australian as well as
the Polynesian Region. Characterized by presence of
Dipneusti. Cichlidae and Characinidae absent.