230 



Lung single, and divided into com- 

 partments. Five pairs of gill - clef t c , 

 four pairs of internal gills and a hyoid 

 half -gill. Larva tadpole-like, but without 

 external gills. Queensland, Mary and 

 Burnett Rivers. 



Protopterus (the African Lung-fish or 

 Mud-fish). Paired fins reduced to 

 long stump-like tapering limbs. Lung 

 double. Gills on the last three arches 

 only. When the dry season sets in, 

 it sinks down into the mud, sinks 

 slowly as the mud stiffens, and so 

 a passage remains open ; then it 

 encapsules itself in a cocoon of 

 secreted mucus. A small hole in 

 the lid of the cocoon is the opening 

 of a narrow mucus pipe leading into 

 the creature's mouth ; and thu? it 

 breathes air by its lungs while it lies 

 dormant in the baked mud. A nest 

 is formed for the eggs, and the male 

 guards them. Larva tadpole-like, 

 with four external gills. Swamps 

 along the White Nile, Congo, and 

 Gambia Rivers. 



Lepidosiren (the South American Lung- 

 fish or Mud-fish). Eel-shaped. Paired 

 fins reduced to stump-like limbs. 

 Lung double. Gills on the last three 

 arches only. Like Protoptenis, it 

 remains dormant in the mud during 

 the dry season ; but the cocoon is 

 simply a bed of slime in which it 

 rests, "the body sharply bent, tin- 

 tail folded over the face." Tin 

 are laid in an excavated burrow. 

 During the breeding season, vascular 

 filaments are developed on the hind 

 limbs of the male ; and this accessory 

 means for efficient breathing enahlo 

 him to remain constantly beside the 

 nest. The larvae, which have four 

 external gills, strikingly resemble 

 larval newts. Chaco of Paraguay, 

 also Brazil. 



