1907.] AFEICAN SILURID FISHES. 1069 



fontanelle small, in advance of the occipital process ; eye 2 (very- 

 young) to 4|- times in length of snout, 3 to 9 times in interorbital 

 width ; width of mouth nearly equal to interorbital width ; band 

 of prsemaxillary teeth 5^ to 8 times as long as broad ; vomerine 

 teeth mostly conical, sometimes subgranular behind, forming a 

 crescentic, continuous or narrowly interrupted band which is as 

 broad as or narrower than prsemaxillary band ; nasal barbel | to 

 I length of head (|- to f in the very young) ; maxillary barbel f 

 to f length of head (|- to once and 4- in the very young), reaching 

 gill-opening or extremity of pectoral spine ; outer mandibular 

 barbel 1| to 1| times as long as inner, which measures ^ to f 

 length of head (f to nearly once in the very young). Gill-rakers 

 rather short, 20 to 27 on anterior arcli. Clavicles hidden under 

 the skin. Dorsal 65 to 76, its distance from occipital process 

 •i- to -^ length of head, its distance from caudal fin 1 to 2^^ 

 diameter of eye. Anal fin with 53 to 62 rays, narrowly separated 

 from caudal. Pectoral f to i length of head, the spine serrated 

 on the outer border and | (young) to f the length of the fin. 

 Ventral slightly nearer end of the snout than root of caudal. 

 Caudal not quite half length of head. Upper parts olive or dark 

 brown, uniform or with darker marblings, lower parts white ; 

 a more or less distinct dark band on each side of the lower surface 

 of the head; fins dark, edged with yellow or orange, sometimes 

 with small black spots. 



Reaches a leng-th of 750 millimetres. 



Nile, Lake Victoria. 



2. Olarias gariepinus. 



SilurtLs {Heterohranchtts) gariepinus Burchell, Trav. Int. S. Afr. 

 i. p. 425, fig. (1822). 



Clarias capensis (non C. & V.) A. Smith, 111. Zool. S. Afr., 

 Pise. pL xxvii. (1845). 



Clarias mossamhicics, part., Peters, Mon. Berl. Ac. 1852, p. 682, 

 and Reise Mossamb. iv. p. 32, pL vi. figs. 1 & 2, and pi. vii. 

 figs. 2 & 3 (1868). 



Clarias gariepimts Giinther, Cat. Fish. v. p. 14 (1864); M. 

 Weber, Zool. Jahrb., Syst. x. 1897, p. 149 ; Boulenger, Poiss. Bass. 

 Congo, p. 254 (1901). 



Depth of body 6| to 7 times in total length, length of head 3 to 

 3g times. Head If to If times as long as broad, its uf)per surface 

 coarsely granulate in the adult ; occipital process angular ; frontal 

 fontanelle 3 to 3j times as long as bi-oad, 4 times in length of 

 head ; occipital fontanelle very small, in advance of occipital 

 process ; eye very small, 3 times in length of snout and 5 or 6 

 times in interorbital width in the adult ; width of mouth nearly 

 equal to interorbital width, f length of head ; band of pr^e- 

 maxillary teeth 5 or 6 times as long as broad ; vomerine teeth 

 mostly conical, or granular-subconical, forming a ci-escentic band, 

 which may be slightly interrupted in the middle, where it is 



71* 



