The Freshwater Fishes of South Africa. 325 



Teeth bicuspid, in single series on entire edge of both jaws ; 

 mouth inferior, below eyes ; nostrils close together, close to the eye ; 

 body short. 



Key to Species. 



12 rows of scales? round caudal peduncle. 



Teeth f ; D. 20-22, A. 27-29 ; Lat. 1. 37-40 1. P. catostoma. 



16 rows of scales round caudal peduncle. 



Teeth ; D. iii 17, A. iii 23 ; Lat. 1. 36 2. P. stuhlmanni. 



PETBOCEPHALUS CATOSTOMA, Gunth. 



Mormyrus catostoma, Gunth., Cat. Fish., vi., p. 222 (1866). 

 Pctrocephalus catostoma, Bouleng., Proc. Zool. Soc., 1898, p. 790, 

 and Cat. Fresh. Fish. Africa, i., p. 57 (1909). 



Teeth, 12 in upper 18 in lower jaw. Depth of body 3 to a little 

 more than 3 times in total length excluding caudal, length of head 

 3^ to 3^ times. Head a little longer than deep, with convex 

 upper profile ; snout short, length of head, rounded, projecting 



FIG. 3. Petrocepjialus catostonut. 



beyond mouth ; mouth situated below eye, its width 1 length of 

 head ; diameter of eye 3 to 5 times in length of head, as long as or 

 slightly longer than snout, and I to nearly equal to interorbital 

 width. 



Dorsal 20-22, originating slightly behind beginning of anal, its 

 length about ^ its distance from head. Anal 27-29, slightly nearer 

 to base of ventral than to base of caudal. Pectorals pointed, f to 

 nearly f length of head, twice as long as ventral and extending 

 beyond base of latter. Caudal with pointed lobes ; caudal peduncle 

 2| to 3 times as long as deep, a little shorter than head. 37-40 

 scales in lateral line, T rows of scales in transverse series on body, 

 yy rows in transverse series between dorsal and anal fins, 12 rows 

 round caudal peduncle. 



Colour (of preserved specimens), silvery, darker on back. 



Five specimens, ranging from 50 mm. to 59 mm. in length, from 

 Kafue Eiver, Upper Zambezi (J. Drury). 



