152 



ZOOLOGY. 



ness, and is coTercd with round scales. Tlie pectoral and 

 ventral fins are long, narrow, and pointed, and tlie verte- 

 bral column extends to the end of the caudal fin, which 

 ends in a point, not being twodobed as in other fishes. 



The Australian lung-fish (Fig. 105) has but a single lung, 

 It attains a length of six feet. It can breathe either by 

 gills or lungs alone. Ordinarily it uses its gills, biit when the 



Fig. 194- — Spoon-bill fish. From Liitkeu's Zoology. 



fish is compelled to live during droughts in thick muddy 

 water charged with gases which are the product of decom- 

 posing organic matter, it is obliged to use its lungs. It 

 lives on the dead leaves of aquatic grasses, etc. The local 

 English name is "fiat-head,"' the native name being "bar- 

 ramundi." 



The African lung-fish (Fig. 196) has two lungs. It lives 



Fia. 195.— Ceraforftw, or Australian Lnng-flsh. (The tail in nature ends in a 



point.) 



on leaves in the White Nile, the Niger, and Gambia rivers, 

 where it buries itself in the mud a foot deep. A similar 

 lung-fish {Lepidosiren) lives in the rivers of Brazil, and 

 the closely allied Profopterus in tropical Africa. Ceraiodus 

 makes use of the lungs mainly when the muddy water is 

 saturated witli gases from organic matter. 

 Finally we come to those American Ganoids whose skelc- 



