THE AUSTRALIAN LUNG-FISH 
381 
like a reptile, and its swimming-bladder is so 
developed that it does duty as low-class lungs. 
Its gills are very small and imperfect, and of 
little use. The top of its skull is quite uidike 
those of other fishes, and its scales are very large. 
Its pectoral and ventral fins are very long and 
leg-like, and are covered with scales everywhere 
save on the edges, where the fin-rays are situated. 
One of the most extraordinary features of this 
strange fish is the possession of large and very 
remarkable molar teeth, those above being set in 
the palate (vomer), and evidently designed for 
the cutting up of vegetable food. Leaving bony 
anatomy out of consideration, it is quite clear 
that the living fish which stands nearest to 
Ceratodus is the jumping fish or mud-skipper, 
of the Malay Peninsula, which hops about on 
land with surprising independence and agility. 
Its long pectoral fins are really foot-like in use- 
fulness. 
Both in the Burnett and Mary Rivers of 
Queensland, where it lives, and also in captivity, 
this Lung-Fish frequently rises to the surface of 
the water to take breath, like a porpoise. 
The allied Mud-Fish ( Lepulosi'ren ) of the 
Amazon, and the African Mud-Fish (Protop' - 
terus) of the River Gambia, have legs that are 
mere wisps of skin and flesh, and strongly re- 
semble our Amphiuma, of the Class Amphibia. 
They are rarely seen alive in captivity. 
