236 SILUEJLD^E. 



Depth of body 5 to 9 times in total length, length of head 3 to 

 3J times. Head 1| to If times as long as broad, its upper surface 

 coarsely granulate in the adult ; occipital process angular or rounded ; 

 frontal fontanelle sole-shaped or knife-shaped, 2£ to 4 times as long as 

 broad, 3£ to 6 times in length of head ; occipital fontanelle small, in 

 advance of occipital process; eye 2 (young) to 4£ times in length of 

 snout, 4 to 7 times in interorbital width ; width of mouth equal to or a 

 little less than interorbital width ; band of prsemaxillary teeth 4 (young) 

 to 6 times as long as broad; vomerine teeth granular, formiug a 

 crescentic band with or without a posterior median process, its greatest 

 width, in the middle, 1| to 2\ times that pig> 19 7. 



of the prsemaxillary band ; anterior man- ^ 



dibular teeth pointed, posterior granular; " ^ ' "\^ 



nasal barbel ^ to § length of head (up to << = /--"bczr -n, I 

 j in the very young) ; maxillary barbel 



Clarias lazera. 

 Lower Nile (F. N.). |. 



usually a little shorter than head, sometimes a little longer (up to once 

 and a half in the very young), reaching extremity of pectoral spine 

 or a little beyond extremity of pectoral fin ; outer mandibular barbel 

 lj to 1§ times as long as inner, which measures f to J- length of 

 head. Gill-rakers long and closely set, 35 (very young) to 135 on 

 anterior arch. Clavicles striated or rugose with granulations, more or 

 less distinct under the thin skin. Dorsal 62-82, its distance from 

 occipital process y to J length of head, its distance from caudal not 

 greater than diameter of eye. Anal 50-65, narrowly separated from 

 caudal. Pectoral § to \ length of head, the spine serrated on the outer- 

 side and | (young) to f the length of the fin. Ventrals equally distant 

 from end of snout and root of caudal, or a little nearer the former. 

 Caudal about half length of head. Greyish olive or olive-brown to 



