4G6 STLL T Mn;E. 



postocular part of head ; eye lateral, 5 (young) to 7^ times in length of 

 head, 2 to 3£ times in interorbital width ; lips strongly developed, 

 forming a large lobe on each side ; prsemaxillary teeth few, in 2 or 3 

 series, a few minute ones behind ; movable mandibular teeth as long as 

 or a little longer than eye, G to 8 in number. Maxillary barbel with a 

 broad marginal membrane at the base, § to i length of head ; mandibular 

 barbels with long, finely tuberculate, slender branches, outer 1^ to 2 

 times as long as inner. Gill-opening not extending downwards beyond 

 root of pectoral spine. Occipito-nuchal shield rough like the occiput, 

 obtusely tectiform, 1\ to 2 times as long as broad, posterior processes 

 obtusely pointed or truncate. Humeral process little longer than broad, 

 flat, granulate, rounded or obliquely truncate, extending as far or not 

 quite so far back as occipito-nuchal process. Dorsal 1 7 ; spine straight 

 or curved, finely serrated in front, coarsely behind, slightly shorter or 

 slightly longer than head, the soft terminal part produced into a short 

 filament. Adipose dorsal 3 to 5 times as long as deep, 4 to 6 times as 

 long as its distance from rayed dorsal. Anal IV 8, acutely pointed. 

 Pectoral spine shorter than dorsal, rarely reaching base of ventral, 

 outer border smooth or very, finely serrated, inner border with strong 

 serrae. Ventral acutely pointed, reaching origin of anal or a little 

 beyond. Caudal very deeply forked, upper lobe the longer and often 

 terminating in a filament. Caudal peduncle nearly as long as deep. 

 Grey above, white below; ra\ed fins light, with a more or less distinct 

 dark blotch on the dorsal near its base, and a dark band along each lobe 

 of the caudal ; barbels white. 



Total length 380 millim. 



Blue and "White Niles. 



1-2. Types. Khartum. J. Petherick, Esq. (C). 



3-i. Ad. Wad Me.Hiie, Blue Nile. L. Loat, Esq. (C). 



5. Ad. Mouth of L. No, White Kile. 



52. SYNODONTIS PLEUROPS. 



Bonleng. Ann. & Mag. N. H. (u'j xx. 181)7, p. 421, and Poiss. Bass. Congo, p. 326 

 (1901). 



Depth of body equal to length of head, 3^ to of times in total length. 

 Head 1^ to li times as long as broad, granulate above from between 

 the eyes ; snout pointed, a little less than \ length of head ; eye lateral, 

 3i to 4 times in length of head, 2\ to 2| times in interoibital width. 

 Lips much developed; piaemaxillary teeth forming a short and broad 



