OPIIIOCEPHALUS. ' ^ 



Depth of 1)0(1) 5 to tl.i times in total hnigtli, Icnglh nl" head 3 to Sh 

 times. Head If to 2 times as long as broad; lower jaw projecting 

 beyond upper; snout rounded, 1 (young) to 2 times as long as eye, 

 which is 5 (young) to 9 times in length of head and U to 2i times in 

 interorbital width ; maxillary extending beyond vertical of posterior 

 border of eve ; a few large canines on each side of lower jaw ; nasal 

 tentacle f to | diameter of eye; 10 to 12 series of scales between eye 

 and angle of praeoperculum. 8- or short gill-rakers on lower part of 

 anterior arch. Dorsal 10-45, longest rays f to f length of head. Anal 

 20-31. Pectoral h to ? length of head, longer than ventral. Caudal 



Fis. 44. 





OiihiocepJtalus olmciirns. 

 Gondokoro (F. N.). ^. 



rounded or subacuminato. Caudal peduncle 1^ to 1| times as deep as 

 long. Scales striated, with entire or feebly denticulate border, G2-76 

 above lateral line, ^^-f, below first dorsal ray ; lateral-line tubes 34-42. 

 Olive above, greyish beneath ; a lateral series of large, rounded, oval, 

 or rhombic dark spots edged with black, sometimes with a light outer 

 border ; irregular blackish spots above and beneath the lateral series ; 

 a broad blackish band along each side of the head, from the eye to the 

 edsre of the sill-cover; lower surface of head marbled with whitish; 

 fins greyish olive, spotted with black. Young with a broad blackish 

 lateral hand to the root of the caudal fin, followed, on the basal part of 

 the latter, by a small, black, light-edged occUar spot. 



'I'otal length 350 millini. 



White Nile. 15a]ir-el-(;el)el, Chad Basin, Senegal to Congo. 



