48 



MOEMYKID.E. 



4. GNATHONEMUS. 



Gill, Proc. Ac. Philad. 1862, p. 443 ; Boulenger, Proc. Zool. Soc. 1898, p. 801, and Poiss. Bass. 



Congo, p. 89 (1901). 

 Campylomormyrus, Bleeker, Versl. Ak. Amsterd. (2) viii. 1874, p. 367. 



Teeth in the jaws small, conical, truncate, or notched, few (3 to 10 in the upper 

 jaw, 4 to 10 in the lower) ; minute conical teeth on the parasphenoid and on the 

 tongue ; mouth terminal. Nostrils moderately far apart, remote from the eye. Body 

 moderately elongate; ventral fins equally distant from the pectorals and from the 

 anal, or nearer the former. Dorsal and anal fins not very unequal in length. 

 Vertebrae 45-49 (10-14+4-8 + 27-30). 



This is the largest genus of the family, thirty-two species being distinguished, five 

 of which occur in the Nile system. 



Synopsis of the Species. 



I. Dorsal and anal fins exactly opposed to each other. 



Dorsal 31 ; anal 33 ; chin slightly swollen; 78 scales in lateral line, 



12 round caudal peduncle 1. G. pictus, Marcus. 



II. Anal fin originating in advance o£ dorsal. 



Dorsal 25-30 ; anal 30-37 ; a globular mental appendage ; 70-86 



scales in lateral line, 16-18 round caudal peduncle 2. G. cyprinoides, L. 



Dorsal 23-25 ; anal 28-32 ; a globular mental appendage ; 56-69 



scales in lateral line, 12-16 round caudal peduncle 3. G. macrolepidotus, Ptrs 



Dorsal 22-25 ; anal 28-31 ; a long, pointed mental appendage ; 



58-64 scales in lateral line, 10-12 round caudal peduncle . . . 4. G. longibarbis, Hilg. 

 Dorsal 17-20 ; anal 25-28 ; no mental appendage ; 51-58 scales in 



lateral line, 12 round caudal peduncle . 5. G. niger, Gthr. 



1. GNATHONEMUS PICTUS. 

 (Plate VII. fig. 2.) 



Mormyrus, sp. n., Heuglin, Sitzb. Ak. Wien, ix. 1852, p. 920, pi. lx. fig. 1. 

 P etrocephalus pictus, Marcusen, Mem. Ac. St. Petersb. (7) vii. 1864, p. 153. 

 Gnathonemus pictus, Boulenger, Ann. & Mag. N. H. (7) xvi. 1905, p. 38. 



Depth of very strongly compressed body three and a half times in the total length, 

 length of head five times. Head as long as deep, twice as long as broad, with curved 

 upper profile ; snout short, rounded, as long as the eye, the diameter of which is four 

 times in the length of the head ; interocular width one-third the length of the head ; 



