SOUTHERN TEMPERATE ZONE. 283 



on comparing the numbers of species constituting a genus. 

 In this zone genera composed of more than ten species are the 

 exception, the majority having only from one to five. 



The proportion of genera limited to this zone is rather 

 high; they will be indicated under the several districts, 

 which we distinguish on geographical rather than zoological 

 grounds. 



1. The Cafpe, of Good Hope district. 



The principal genera found in this district are the follow- 

 ing (those limited to the entire zone being marked with a 

 single (*) and those peculiar to this district with a double (**) 

 asterisk) : — 



Chimccra, * Callorhynchus, Galeus, ** Leptocarcharias, Scyl- 

 lium, Acanthias, Bhinohatus, Torpedo, Narcine, Astrape, Raja. 



Serranus, Dcntcx, Pristipoma ; Cantharus, Box, **Dipterodon, 

 Sagrus, Pagrus, Pagellus, Chrysophrys ; Chilodadylus ; Sebastes, 

 *Ag7'iop)us ; Trigla ; Sphyrcena ; Lepidopus, T]iyrsitcs ; Zeus; 

 Garanx ; Loplims ; Clinus (10 species), Gristiceps ; **Ghoriso- 

 chismus. 



** Halidesmus, *Genypterus, Motella. 



Syngnathus. — '^Bdellostonia. 



This list contains many northern forms, which in conjunc- 

 tion with the peculiarly southern tyjDes {Callorliynclms, Ghilo- 

 dactylus, Agriopus, Clinus, Genypterus, Bddlostdma) leave no 

 doubt that this district belongs to the southern temperate 

 zone, whilst the Freshwater fishes of South Africa are mem- 

 bers of the tropical fauna. Only a few (BJiinohatus, Nar- 

 cine, Astrape, and Sp)hyraina) have entered from the neigh- 

 bouring tropical coasts. The development of Sparoids is 

 greater than in any of the other districts of this zone, and 

 may be regarded as one of its distinguishing features. 



2. The South Australiaii district comprises the southern 

 coasts of Australia (northwards, about to the latitude of 



