SOUTHERN ZONE. 249 



from Kerguelen's Land, or .from islands beyond 55° lat. S. 

 The southern extremity of Africa has to be excluded from 

 this zone so far as Freshwater fishes are concerned. 



This zone is, with regard to its extent as well as to 

 the number of species, the smallest of the three ; yet its 

 ichthyological features are well marked ; they consist in the 

 presence of two peculiar families, each of wliich is analogous 

 to a northern type, viz. the Haplochitonidce, which represent 

 the Salmonidce, Haplocldton being the analogue of Scdmo, and 

 Prototroctes that of C or eg onus ; and the Gcdaxiidm, which are 

 the Pikes of the Southern Hemisphere. 



Although geographically widely separate from each other, 

 the Freshwater fishes of the three divisions are nevertheless 

 so closely allied that conclusions drawn from this group 

 of animals alone would hardly justify us in regarding these 

 divisions as sub-regions. One species of Galaxms (G. attenu- 

 atus) and the three Lampreys are found in all three, or at 

 least two, sub-regions. 



Freshwater Fishes of the Soidhern Zone. 



Tasmanian. N. Zealand. Fuesian. 



11 



But little remains to be added in explanation of this 

 list; Percichthys is in Chili the autochthont form of the cos- 



