LUNG-FISHES. 



301 



throw doubts on the validity of this genus, and to show that both the African and 

 the American forms are congeneric. 



JProtopterus annectens, the form which frequently figures in museums as the Lepi- 

 dosiren is a much more common species. It is found throughout the whole of tropical 

 Africa, but apparently is most common near the west coast. It inhabits fresh water, 

 and feeds exclusively on fish, frogs, insects, and other animals. The body is much like 

 that of the true Lepidosiren, but the pectoral and ventral fins have a slight fringe ; 

 and three external gill-like appendages protrude from the gill-clefts. It is covered 

 with rather small cycloid scales, and reaches a length of about six feet. During the 



Fig. 169. — Frotoptarus annectens, doko, komtok. 



dry season, many of the ponds dry up, but before they are completely desiccated, the 

 Protopterus descends some distance into the mud, and forms a rounded hollow for a 

 nest. In this it lives until th« rainy season releases it. The mud around one of these 

 nests becomes very hard, and the balls thus formed have been dug out, and, without 

 breaking, have been brought to Europe, and to this country. A short immersion in 

 water serves to release the fish, which will live for some time in confinement. When 

 water is plenty, the fish breathes by its gills, but when the ponds dry up, it is forced 

 to depend upon its lungs; though, from its torpid condition, it needs but comparatively 

 little oxygen. The natives are fond of the flesh, and in some parts of the interior it 

 forms a considerable element in the food supply. 



