Animals Before Man 



Associated with tlie " fislies " just described, 

 during the latter part of their career, were 

 others more like those of to-day ; in fact, one or 

 two of them are represented by living species. 

 Such are the so-called lung-fishes,* the Aus- 

 tralian Ceratodus, the African Protopterus, and 

 his South American cousin, Lepidosii'en, the 

 last two also known as mudfishes, from their 



Ceratodus forsteri, a modern limg-fish from Australia. 



habit of passing the dry season ensconced in a 

 mass of dried mud. These form the subclass 

 Dipnoi, whose members present some resem- 

 blances to the amphibians — another instance 

 of the interrelation of living beings. Owing 

 to this, as well as to their great antiquity, these 

 fishes are of special interest, and their struc- 



* So named because the air-bladder, which is present in many 

 fishes, in this group opens into the gullet, and is so modified as to 

 serve the purposes of a lung. 



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