214 MORMYKID^. 



Fam. 10. MORMYRIDtE. 



Monnyri, Mitll. Abhandl. Akad. Wiss. Berl. 1844, p. 189. 



Body and tail scaly, head scaleless; barbels none. 

 The margin of the upper jaw is formed in the middle 

 by the intermaxillaries which coalesce into a single 

 bone, and laterally by the maxillaries. Interopercu- 

 lum sometimes rudimentary. On each side of the 

 single parietal bone a cavity leading into the interior 

 of the skull, and covered with a thin bony lamella. 

 All the fins well developed ; no adipose fin. A series 

 of pores along the base of the dorsal and anal fins. 

 Pseudobranchiae none ; gill-opening reduced to a short 

 slit. Air-bladder simple. Two caeca pylorica behind 

 the stomach. 



Rivers of tropical Africa. 



On the anatomy of the fishes of this family, and especially on the 

 gelatinous band-like bodies situated on each side of the tail, which 

 have been erroneously believed to be electric organs, see Eiippell, 

 ' Fortsetzung der Beschreibung neuer Pische im Nil entdeckt,' p. 9 ; 

 Gemminger, ' Electrisches Organ von Mormijrus ; ' Erdl, Abhandl. 

 Bayr. Akad. Wiss. p. 209 ; Kolliker, Bericht von der zootom. An- 

 stalt zu Wiirzburg, 1849 ; Valenciennes in the ' Histoire Naturelle 

 des Poissons,' II. cc. ; Hyrtl, Denkschr. Akad. Wiss. Wien, 1856, xii. 

 p. 1 ; Marcusen, Mem. Acad. Sc. St. Petersb. 1864, t. vii. 



The species of this family may be referred to the foUowing 

 genera : — 



A narrow band of pointed teeth along the middle of the palate and of the tongue. 



1. MORMYRUS, p. 214. 



A broad pateh of obtuse, molar-like teeth on the roof and bottom of the mouth. 



2. Hyperopisus, p. 222. 

 No teeth on the palate or on the tongue 3. Moemyeops, p. 223. 



1. MORMYRUS*. 



Mormyrus, sp., i/. Syst. Nat. i. p. 522 ; Geoffr. Descr. Eg. Zool. i. p. 265. 

 Mormyrus and Mormyrops, sp., Mull. Berl. Ahhandl. 1844, p. 190. 

 Morinvrodes, Gnathonemus, Petrocephalus, Gill. Proc. Acad. Nat. Sc. 

 Philad. 1862, p. 443. 



A narrow band of pointed teeth along the middle of the palate 

 and of the tongue. 



* 1. Mormi/rus juhilini. C. & V. six. p. 252. — D. 85. A. 19. — Senegal. 

 2. nacra, C. & V. xix. p. 2u7. — Nile. 



