NANNOCHARAX. 279 



17. NANNOCHARAX. 



Giinth. Ann. & Mag. N. H. (3) xx. 1867, p. 112 ; Bouleng. Poiss. Bass. Congo, 

 p. 196 (1901), and Fish. Nile, p. 150 (1907). 



Snout short ; mouth very small, inferior, each jaw with a single series 

 of small, notched, bicuspid teeth ; maxillary toothless, moderately large. 

 Cheek covered by the suborbitals ; nostrils close together, near the eye, 

 separated by a valvular flap ; gill-membranes free on the sides only. 

 Body more or less elongate, cylindrical or compressed. Scales small, 

 strongly ciliated ; lateral line straight, equally distant from the dorsal 

 and the ventral outlines ; a scaly process at base of ventral fin. Dorsal 

 fin with V2 to 15 rays, above the ventrals ; anal fin with 10 or 11 rays; 

 a small adipose dorsal fin. Vertebra 43-44 (21-22 -(- 22.) 



Nile and Tropical Africa. 



Synopsis of the Sj)ecies. 



I. Doisal originating above ventrals, with 9 to 11 branched rays. 

 A. Lateral line complete. 



1. Not more than 50 scales in lateral line, 4^ or 5 in transverse series 



above lateral line ; length o£ head 3f to 4^ times in total length. 

 Head deeper than broad ; depth o£ body 4^ 

 to 5 times in total length ; pectoral as 

 long as head, extending beyond root o£ 

 ventral ; So. 37-38 ^ I. N. brevu, Blgr., p. 280. 



Head deeper than broad ; depth of body 3f to 

 4y times in total length ; pectoral much 

 shorter than head, not reaching root of 

 ventral ; Sc. 38-40 ^ 2. iV. pamw, Pellegr., p. 281. 



Head not deeper than broad ; depth of body 

 5 to 5^ times in total length ; pectoral 

 as long as head, extending beyond root of 



ventral ; Sc. 42-49 „1^ 3. N. fasciatus, Gthr., Tp. 281. 



2. 47 scales or more in lateral line, 5^ or 6 in transverse series above lateral 



line ; length of head 4 to 5 times in total length. 

 Head deeper than broad ; depth of body 5 to 

 5^ times in total length ; pectoral as long 

 as head or slightly shorter, extending a 

 little beyond origin of ventral ; Sc. 47-55 

 ^, 4. X interinedius, Blgr., p. 282. 



