MORMYRID FISHES. 



87 



gelatinous substance enclosed in regularly arranged connective 

 tissue compartments and supplied with enlarged spinal nerves. 

 In all except Gymnarchus there are slender bones, known as 

 Gemmingerian bones, occurring on each side of the tail, above 

 and below the electric organ, the equivalents of which bones have 

 not been recognised in any other fishes. The flesh of Mormyrid 

 fishes is good, and one species, Mormyrops deliciosus, 241, 

 derives its specific name from its excellent flavour. Mormyrus 

 oxyrhynchus (238, and fig. 48) was venerated by the ancient 

 Egyptians, and the outline of the fish appears frequently in their 

 pictures. The long-snouted forms like Gnathonemus curvirostris, 

 242, search for their food in the mud and beneath stones, the 

 finger-like process on the chin acting as a " feeler," the sensi- 



Fig. 48. — Mormyrus oxyrhynchus. 

 (From Gunther, " Study of Fishes.") 



tiveness of which compensates for the reduction in the power of 

 distinct vision. The species with larger mouths seize small 

 fishes and crustaceans. Gymnarchus niloticus, 243, of the Nile 

 and rivers of West Africa, has a long, eel-like body, without 

 caudal, anal, and pelvic fins. The dorsal fin extends the whole 

 length of the body. The jaws have well-developed, chisel-edged 

 teeth. The air-bladder is cellular and very extensible, and is an 

 important organ of respiration. Gymnarchus moves through the 

 water by the action of its dorsal fin only ; it can move backwards 

 as readily as forwards, and when retreating uses its tapering tail 

 as a feeler. The fish makes a floating nest, which the male 

 guards jealously ; the young have external gill-filaments and 



