5l6 FISHES CHAP. 



visible than if opaque. Tlie commencement of pulmonary respira- 

 tion is coincident with the degeneration of the cutaneous gills, 

 which takes place about seven weeks after the deposition of 

 the eggs, and about a month after the larvae leave the nest. 

 Protopterus is said to attain a length of six feet. 



Lepidosiren paradoxa} probably the only species of the 

 genus, i.s confined to South America. It occurs along the 

 course of the main Amazon river, entering some of its larger 

 affluents, such as the Ucayale, the Madeira, the Eio ISTegro, and 

 the Tapajoz, and also in the Chaco Boreal to the west of the 

 Upper Paraguay river. The home of the Lepidosiren (or 

 " Lolach," as the natives call the Fish) of the Chaco country is 

 to be found in the wide -spreading marshes and swamps, which 

 for a great part of the year are almost choked by a luxuriant 

 growth of their own peculiar vegetation and covered by a float- 

 ing carpet of surface weeds, with here and there deeper and 

 clearer water and slow-flowing streams. In the dry season the 

 water gradually shrinks and the swamps eventually become dried 

 up. Of sluggish habits, the Fish wriggles slowly about at the 

 bottom of the swamp like an Eel, using its hind limbs in an 

 irregular bipedal fashion as it wends its way through the dense 

 network of subaqueous plants. Lepiidosiren is not exclusively 

 carnivorous. The large fresh-water snail, Ampullaria, which lives 

 in the swamps in enormous numbers, seems to be its favourite 

 food ; but masses of confervoid Algae are also eaten, and in its 

 earlier stages it is probable that the Fish is more herbivorous 

 than carnivorous. The Jacare {Caiman sclerops) feeds on Lepi- 

 dosiren, and this fact, and probably also the cannibal habits of 

 the Fish itself, may explain the capture of specimens with muti- 

 lated tails and regenerated, branched, pectoral limbs. Like other 

 living Dipneusti, Lepidosiren rises to the surface to breathe. The 

 intervals are, however, very variable, and no doubt depend on the 

 relative purity or impurity of the water. Both expiration and 

 inspiration are said to take place through the mouth. The snout 

 is protruded on the surface, and the creature expires. After 

 being withdrawn for a moment the head is again projected, and 

 inspiration takes place through the partially open lips. When 



1 Bohls, OiiU. Nachriehten, 1894, p. 84 ; Lankester, Trans. Zool. Soc. xiv. Pt. i. 

 1896, p. 11 ; Goeldi, xiv. Pt. vii. 1898, p. 413 ; Graham Kerr, Phil. Trans. (B), 

 192, 1900, p. 299. 



