370 



ZOOLOGY. 



living species, but these are especially interesting to the zoologist from 

 the fact that they may represent the division of fishes from which the 

 air-breathing vertebrates sprang. One genus (Ceratodus) is found in the 

 rivers of Queensland; the second (Protopterus) in the rivers of southern 



FIG. 185. 



FIG. 185. Sheepshead. Greatly reduced. Photographed from life by Dr. R. 



Shufeldt. 



W. 



FIG. 186. 



FIG. 1 86. Young of the Snowy Grouper (Epinephelus niveatus). Photo from life by 

 Dr. R. W. Shufeldt: American Naturalist. 



Africa, and a third (Lepidosiren} in the Amazon in South America. No 

 marine forms are known. From fossil remains it is evident that the 

 ancestors of the present lung-fishes were very much more widely 

 distributed. 



