SYNODONTIS. 391 



28. SYNODONTIS. 



Cuv. Regne Anim. ii. p. 203 (1817) ; Cuv. & Val. Hist. Poiss. xv. p. 244 (1840) ; 

 Glinth. Cat. Fish. v. p. 210 (1864) ; Vaill. N. Arch. Mus. (3) vii. 1895, 

 p. 233. & viii. 1896, p. 87 ; Bouleng. Poiss. Bass. Congo, p. 301 (1901), and 

 Fish. Nile, p. 350 (1907). 



Brachysynodonlis, Bleek. Nederl. Tijdschr. Dierk. viii. 1863, p. 54. 



P seudosynodontis, Bleek. t. c. p. 55. 



Ilemisynodontis, Bleek. 1. c. 



Leiosynodontis, Bleek. 1. c. 



Body short or moderately elongate, more or less compressed. Dorsal 

 fin short, formed of a strong spine and 6 or 7 branched rays ; a large or 

 very large adipose dorsal fin. Pectoral with a' strong spine. Ventral fin 

 with 7 rays, inserted behind the vertical of the dorsal. A cephalo-nuchal 

 bony shield, united to the clavicular bones. Three pairs of barbels : 

 maxillary and two mandibulars, all or at least the latter branched. 

 Nostrils widely separated from each other, the anterior tubular. Eyes 

 lateral or supero-lateral, with free border. Mouth with more or less 

 developed lips ; a band or series of conical praemaxillary teeth ; movable, 

 slender, more or less curved teeth implanted in the lower lip, usually 

 followed by small teeth on the lower jaw; palate toothless. Gill- 

 membranes confluent with the skin of the isthmus. Air-bladder large, 

 free. 



Vertebrae 36-44 (13-17 + 22-27). 7 branchiostegal rays. Intestine 

 very elongate, forming numerous convolutions. 



Nile and Tropical Africa. 



Synopsis of the Species. 



I. Maxillary barbel not branched ; gill-opening not extending downwards 

 beyond base of pectoral fin. 

 A. Movable mandibular teeth 70 to 80 ; band of prsemaxillary teeth rather 

 lono- extending along the whole width of the mouth ; head smooth 

 above, or with feeble vermicular rugosities; snout longer than post- 

 ocular part of head. 

 Adipose dorsal 2\ to 2>\ times as long as its 

 distance from rayed dorsal ; caudal lobes 

 produced into long filaments ; skin not 



villose 1. S. caiulalis, Blgr., p. 397. 



Adipose dorsal 1| times as long as its distance 



from rayed dorsal ; skin villose on sides . 2. S. polyodon, Vaill., p. 398. 



