516 FISHES CHAP. 
visible than if opaque. The 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, is confined to South America. It occurs along the 
course of the main Amazon river, entering some of its larger 
aftluents, such as the Ucayale, the Madeira, the Rio Negro, and 
the Tapajéz, 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. Lepidosiren 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being withdrawn for a moment the head is again projected, and 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, Gétt. Nachrichten, 1894, p. 84; Lankester, Z’rans. Zool. Soc. xiv. Pt. i. 
1896, p. 11; Goeldi, xiv. Pt. vii, 1898, p. 413; Graham Kerr, Phil. Trans. (B), 
192, 1900, p. 299. 
