470 



SILUKID^. 



sometimes extending a little on the snout ; snout pointed, as long as 

 or longer than postocular part of head ; eye lateral or nearly so, its 

 diameter 4^ (young) to 6 times in length of head, If to 3 times in 

 interorbital width. Mouth narrow, with strongly developed lips, forming 

 a large lobe on each side; praemaxillary teeth few, in 1, 2, or 3 series, 

 sometimes with a few minute ones behind ; movable mandibular teeth 

 -| to once diameter of eye, 6 to 9 in number. Maxillary barbel with a 

 distinct marginal membrane at the base and with long, slender, finely 

 tuberculate branches, its length f to nearly once that of head ; mandi- 

 bular barbels with long, tuberculate branches, the outer inserted further 



Fig. 352. 



Synodontis clarias. 

 Mouth of L. No (F. N.). |. 



back than and 1^ times as long as the inner. Gill-opening not extending 

 downwards beyond root of pectoral spine. Occipito-nuchal shield rough 

 like the occiput, obtusely tectiform, If to 2 times as long as broad; 

 posterior processes obtuse or truncate. Humeral process subtriangular, 

 flat, granulate, not extending so far back as occipito-nuchal process. 

 Dorsal I 7 ; spine strongly curved, more or less distinctly finely serrated 

 in front in its basal half, strongly serrated behind, as long as or longer 

 than head, the soft terminal part produced into a short filament. 

 Adipose dorsal 3 to 4-^ times as long as deep, 4 to 8 times as long as its 

 distance from rayed dorsal. Anal V 7-9, acutely pointed. Pectoral 

 spine shorter than dorsal, sometimes reaching ventral, outer border 

 feebly serrated, inner border strongly serrated. Ventral acutely pointed, 



