30 MORMYEID-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 subinferior ; dorsal fin a little longer 



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



j3. 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. 60. 



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. 6. Myomyrus, Blgr., p. 92. 



Mouth terminal ; dorsal and anal equal or sub- 

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



2. Teeth in jaws disposed in several rows 

 forming villiform bands ; dorsal and 



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

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



Mouth terminal 9. Mormyrus, L., p. 126. 



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

 Mouth terminal ; palate and tongue with a 



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



II. Gtmnarchin^e. — Ventral, anal, and caudal 

 fins absent; no teeth on the parasphenoid 

 and tongue; body eel-shaped .... 11. Gymnarchus, Cuv., p. 144. 



1. M0RMYR0PS. 



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



Mormyrops, part., J. Mull. Arch. f. Nat. 1843, p. 324 ; Giinth. Gat. Fish. vi. 



p. 223 (1866). 

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



p. 88 (1868) ; Bouleng. Proc. Zool. Soc. 1898, p. 780, Poiss. Bass. Congo, 



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

 Oxymormyrus, Bleek. Vers!. 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 (10-30 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 



