30 MORMYfllD-E. 



b. Teeth only in the middle of the jaws, 3-10 in each jaw. 



a. Body much elongate ; ventral fin nearer anal than pectoral. 

 Mouth subiuferior ; dorsal fin a little longer 



than anal 3. IsicJithys, Gill, p. 59. 



y8. Body short or more or less elongate; ventral fin equally distant from 

 pectoral and anal or nearer the former. 

 Mouth inferior or subinferior, below level of 

 eye ; teeth moderate or small ; posterior 



nostril remote from mouth 4. Marcusenius:, Gill, p. GO. 



Mouth inferior or subinferior ; teeth small ; 



posterior (lower) nostril close to mouth . . 5. Stomatorhinus, Blgr., p. 87. 

 Mouth inferior ; upper teeth small, conical, 

 median pair of mandibular teeth very large, 



incisor-like ; dorsal much longer than anal. G. Myomyrus, Blgr., p. 02. 

 Mouth terminal ; dorsal and anal equal or sub- 

 equal in length 7. Gnatlionemus, Gill, p. 94. 



2. Teeth in jaws disposed in several rows 

 forming villiform bands ; dorsal and 

 anal fins nearly equally developed . 8. Genyomyras, Blgr., p. 125. 



B. Anal fin less than half the length of the dorsal. 

 Mouth terminal 9- Mormyrus, L., p. 12G. 



G. Anal fin more than five times the length of the dorsal. 

 Mouth terminal ; palate and tongue witii a 



pavement of large spheroid teeth . . . .10. Jlyperopisus, Gill, p. 142. 



II. Gymnarchin^. — Ventral, anal, and caudal 

 fins absent; no teeth on the parasphenoid 

 and tongue; body ocl-shappd . . . .11. Gymnarchiis, Cuv., p. IH. 



1. MORMYROPS. 



Mormyrus, part., Linn. Syst. Nat. i. p. 522 (1766). 



J\formyrops, part., J. Mull. Arch. f. Nat. 1843, p. 324 ; Giinth. Cat. Fish. vi. 



p. 223 (1866). 

 Mormyrops, Gill, Proc. Ac. Philad. 1862, p. 139 ; Peters, Reise Mossamb. iv. 



p. 88 (18G8) ; Bouleng. Proc. Zool. See. 1898, p. 780, Poiss. Bass. Congo, 



p. 56 (1901), and Fish. Nile, p. 29 (1907). 

 Oxymormyrus, Bleek. Versl. Ak. Amsterd. (2) viii. 1874, p. 367. 



Teeth in the jaws conical, truncate, or notched, forming a single 

 complete series on the entire edge of both jaws (10-3G in each); 

 minute conical teeth on the parasphenoid and on the tongue; mouth 

 terminal or subinferior. Nostrils moderately far apart, remote from the 

 eye. Body more or less elongate; ventral fins equally distant from 



