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LUNG-FISHES. 



mud and leaves at the bottom, it rises at intervals to the surface to obtain more 

 complete oxygenation of its blood by the inhalation of atmospheric air into its 

 lungs, although its general breathing is carried on by the gills. A grunting noise 

 sometimes uttered by this fish is probably produced by the expulsion of the air 

 from the lungs when it rises to the surface. Although frequently termed the 

 barramundi — a title apparently properly belonging to a totally different fish 

 (Osteoglossum) — it appears that the proper native name of the Australian lung-fish 

 is djelleh. The breeding-season is at its height in September and October, but 

 lasts from April till the beginning of November ; and the eggs, which are enveloped 

 in a gelatinous coat, and are heavier than water, take some ten days to hatch. 

 South American. The mud-fish of the Amazons (Lepidosiren paradoxa) is the sole 

 Mud-Fish. representative of a genus distinguished from the last by the eel-like 

 form of the body, on which the continuous vertical fin extends nearly to the neck, 

 and by the reduction of the limbs to mere tapering filaments, owing to the dis- 



SOUTH AMERICAN MUD-FISH (J- nat. size). 



appearance of the marginal fringe. The vomerine teeth are conical and pointed, 

 and the palatal teeth have strongly marked cusps supported by vertical ridges. 

 There are five gill-arches, with four intervening clefts, but there are no external 

 appendages above the gill-opening. In adult males the upper surface of the hind- 

 limb is beset with tufts of tentacle-like papillae. This mud-fish grows to a length 

 of about 4 feet, and occurs not only in the Amazon and its tributaries, but likewise 

 in the swamps of the Chako country forming the tributaries of the upper Paraguay 

 River. The southern form has been regarded as a distinct species, although the 

 differences are so slight as scarcely to merit such a distinction. These fish feed 

 chiefly on the large molluscs known as ampullariae, which are found collected in 



