348 NATURAL HISTORY OF AFRICA. 



Of the salmon genus, the Salmo fuhus, a fierce and hun- 

 gry fish, is much esteemed as an article of food by the inha- 

 bitants of Guinea. The notable genus Polypterus was first 

 scientifically distinguished by M. GeofTroy. Its shape ig 

 long, cylindrical, and serpentifonn ; the head is defended 

 by large bony plates ; and the body is covered by strong 

 scales, resembling those of a coat of mail. This fish is 

 called bichin by the Egyptians, and is considered as very 

 rare. It is said to dwell in the soft mud of the Nile, and is 

 the finest flavoured of all the Nilotic fishes ; but as it is 

 hardly possible to open the skin with a knife, the fish is first 

 boiled, and the skin afterward drawn off almost entire. The 

 tooth-tongued argentine {A. Glossodonta) is a beautiful spe- 

 cies, native to the Red Sea ; and the pearl-bladdered argen- 

 tine {A. Sphyrana) is a Mediterranean fish of the same ge- 

 nus. The air-bladder of this species is equally bright and 

 beautifiil with its external parts, and along with these is 

 much used in the preparation of artificial pearls. 



The flying-fish {Exocatus exiliens) is remarkable for the 

 great length of its pectoral fins, which enable it to sustain 

 itself above the waves for several hundred yards. The 

 silvery polyneme (P. Niloticus) is a very elegant fish, of 

 great excellence as an article of food. Its mode of capture 

 in the Nile is described by Bruce. The ten-fingered poly- 

 neme (P. decadactylus), likewise esteemed a very wholesome 

 and agreeable fish, occurs along the coasts of Guinea, and 

 occasionally enters the rivers of that country. Of fishes 

 allied to the herring, Africa produces several species. The 

 Cbipea Africana is said to be extremely plentiful during the 

 summer months in the last-named district ; and the dorab 

 herring ( C. dorab) is described by Forskall as native to the 

 Red Sea. Among the carp tribe we shall merely mention 

 the Cyprinus gonorhynchus, mentioned by Gronovius as an 

 inhabitant of the Cape seas. We may observe in passing, 

 that a great variety of fish are caught in the salt waters 

 which environ the Cape ; but fresh fish are there so rare, 

 that Mr. Burchell " does not recollect having seen any at 

 table except eels, and these were regarded as a curiosity."* 

 The genus Mormyrus seems almost entirely peculiar to the 

 NUe. 



Of the cartilaginous fishes, several species of ray inhabit 

 ♦ Travels, vol. i. p. 79. 



