MOKMYBOPS. 29 



B. Anal fin less than half the length of the dorsal, with not more 



than 26 rajs ; mouth terminal . . 5. Mormyrus, L. 



C. Anal fin more than five times the length of the dorsal, with 



more than 50 rays ; mouth terminal . 6. Hyper opisus, Gill. 



II. Gymnarchin^e. — Ventral, anal, and caudal fins absent ; no teeth 

 on the parasphenoid and tongue ; vertebrae more than 100 ; 

 Gemmingerian bones absent (cf. PL XIII.) ; scapular foramen 

 in the coracoid 7. Gymnarchus, Cuv. 



1. M0RMYE0PS. 



J. Miiller, Arch. f. Nat. 1843, p. 324 (part.) ; Boulenger, Proc. Zool. Soc. 1898, p. 780, and Poiss. 



Bass. Congo, p. 56 (1901). 

 Oxy mormyrus, Bleeker, Verh. 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 to 36 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 the pectorals and from the anal, or nearer the former. Anal fin longer 

 than the dorsal. Vertebra? 56-02 (21-24 + 31-39). 



This genus is represented by 17 species, most of which inhabit the Congo. Only 

 one species is found in the Nile. 



1. MORMYROPS ANGUILLOIDES. 

 (Plate V. fig. 1.) 



Mormyrus anguilloides, Linnaeus, Mus. Ad. Frid. ii. p. 110 (1764), and Syst. Nat. i. p. 522 (1766) ; 

 I. Geoffroy, Descr. Egypte, Poiss. p. 271, pi. vii. fig. 2 (1827); Rifaud, Voy. Egypte, 

 pi. clxxxviii. fig. 2 (1836) ; Cuvier & Valenciennes, Hist. Poiss. xix. p. 258 (1846) ; Marcusen, 

 Mem. Ac. St. Petersb. (7) vii. 1864, no. 4, p. 132 ; Giinther, Petherick's Trav. ii. p. 257 

 (1869). 



Mormyrus dendera, Lacepede, Hist. Poiss. v. p. 621 (1803). 



Mormyrops anguilloides, Marcusen, Bull. Ac. St. Petersb. xii. 1854, p. 14 ; Giinther, Cat. Pish. vi. 

 p. 233 (1866) ; Boulenger, Proc. Zool. Soc. 1898, p. 782. 



Marcusenius anguilloides, Gill, Proc. Ac. Philad. 1862, p. 444. 



Depth of body five to six and a half times in the total length, length of head four 

 times. Head once and two-thirds to nearly twice as long as deep, the upper profile 

 slightly concave ; snout rounded, one-fifth to one-fourth the length of the head, 



