87. MALAPTERURUS. 219 



Twelfth Group. MALAPTERURINA. 



Stenobranchiate Siluroids without rayed dorsal fin. The an- 

 terior and posterior nostrils are remote from each other. 



Tropical Africa. 



That this group belongs. to this subfamily, and not to the following, 

 is proved by the rudimentary interneural spine, which rests in the 

 cleft of the neural process of the first vertebra, and clearly shows 

 that if the dorsal fin had been developed, it would have been quite 

 on tlie fore part of the trunk, far in advance of the ventral fins. 

 This rudimentary interneural spine was first discovered by Hyrtl 

 (Denkschr. Acad. Wiss. Wien, 1859, xvi. p. 11). 



87. MALAPTERURUS. 

 Malapterurus, Lacep. v. p. 90. 



Only one dorsal fin, which is adipose, and situated before the caudal ; 

 anal of moderate length or short ; caudal rounded ; ventrals six- 

 rayed, inserted somewhat behind the middle of the body ; pectorals 

 without pungent spine. Barbels six : one to each maxillary, and 

 two on each side of the mandible. Both jaws with bands of villiform 

 teeth ; palate edentulous. The entire head and body covered with 

 soft skin. Eyes small. Gill-opening very narrow, reduced to a slit 

 before the pectoral. An electric organ extends over the whole body, 

 and is situated between two aponeurotic membranes below the ex- 

 ternal integument. 



Rivers of tropical Africa. 



1. Malapterurus electricus. 



Torpedo, Purchas, Pilgrimes, ii. pp. 1183, 1546, 1568. 



Raja torpedo, Forsh. Faun. Arab. ,p. 15. 



Silirrus electricus, L. Gm. i. p. 1354 ; Broms. Mem. Acad. Sc. 1782, 

 p. 692. tab. 62, and Journ. de Phys. xxvii. p. 143 : Bl. Schn. p. 384. 



Malapterurus electricus, Lacep. v. p. 91 ; Geoffr. St.-Hil. Ann. Mus. 

 1802, i. p. 392. pi. 26, and Descr. Eg. Poiss. pi. 12 ; Rudolphi, Abhandl. 

 Berl. Acad. 1824, p. 137; Joannis, in Guer. Mag. Zool. 1835, tab. 1 

 (bad) ; Cuv. §•. Val. xv. p. 518. pi. 455 ; . Valenc. in Ann. Sc. Nat. 1840, 

 2 s6r. xiv. p. 241, and Arch. Mus. 1841, ii. p. 43 ; Cuv. BJgne Anitn. 

 III. Poiss. pi. 99 ; Peters, in Midi. Arch. Anat. 1845, p. 375 ; Pacini, 

 in Nuov. Ann. Sc. Nat. Bologn. 1846, 2 ser. vi. p. 41 ; Bilharz, das 

 electrische Organ des Zitterwelses (Leipzig, 1857, fol.) ; Schultze, zur 

 Kenntniss der electrkchen Organe der Fisclie (Halle, 1858, 4to). 



A. 10-13. Eye rather small, its diameter being a little less than 

 one-third of its distance from the upper end of the gill-opening. 

 The, length of the head is contained four times and a third in the 

 total (without caudal). Jaws equal in front. The outer mandibulary 

 barbels extend to the root of the pectoral. Body with more or less 

 numerous small roundish black spots, a part of which arc sometimes 



