356 



NATURAL HISTORY. 



LUNG-FISHES. 



A very few forms from tropical countries are grouped together as lung- 

 fishes, since they have the air-bladder modified into a lung-like organ. 

 Sometimes there is but one of these lungs, and in other forms there are 

 two, as in the higher vertebrates. Though highly interesting to the natu- 

 ralist, these forms have but little to attract the ordinary person ; or perhaps 

 it would be better to say that we know but little about their habits. 



Fig. 328. — Lung-fish (Protopterus annectans) . 



Of the one-lunged forms there are two living species in Australia, 

 known to the natives as barrmunda, while the colonists call them flat- 

 heads. The flesh is good, but the fishes do not seem to be very abundant. 



One of the two-lunged forms comes from Brazil, but it is among the 

 rarest of all fishes. The other type is African, and is much better knoAvn. 

 It is the doko, or komtok, of the natives, and the Protojrterus of science. 

 Its general appearance is shown in our cut. It lives in rivers and ponds. 



