368 



SILURID^. 



times. Head moderately depressed, If to If times as long as broad, 

 its upper surface and the operculurai rough with granular asperities and 

 covered with a very thin skin ; occipital process rounded, as long as 

 broad or broader than long, in contact with or narrowly separated from 

 a large, granulate interneural shield ; snout pointed, ^, or slightly more 

 than -|, length of head (measured to base of occipital process) ; eye 

 supero-lateral, 2 J (youDg) to 4^ times in length of the snout, 5 (young) 



rig. 285. 



Auchenorjldnis bi^ciitatus. 

 Gondokoro (F. N.). i 



to 8| times in length of head, If (young) to 3 times in interorbital 

 width ; mouth small, nearly terminal, with thick papillose lips ; pra;- 

 maxillary teeth in two small, oval or pyriform longitudinal groups, close 

 together. Maxillary barbel f to |- length of head, reaching more or less 

 behind posterior border of eye ; outer mandibular barbel as long as or a 

 little longer than maxillary, more than twice as long as inner mandibular, 

 which is inserted on lower lip. Gill-rakers rather long and widely set, 

 9-11 on lower part of anterior arch. Humeral process small, acutely 

 pointed, granulate. Dorsal I 7 ; spine strong, with granular asperities 

 in front, i- to f length of head. Adipose dorsal 2\ to 3 times as long 

 as deep, 2 to 2^ times as long as rayed dorsal, from which it is separated 

 by a space equal to y to ^ its own length, extending nearly to root of 

 caudal. Anal 10-12 (6 or 7 rays branched). Pectoral reaching or 

 nearly reaching ventral, spine very strong, granulate on outer side, with 



