MABCUSEIVIUS. 75 



1-4. MARCUSENIUS NIGRICANS. 

 BoulcM-ig. Ann. & Mag. N. H. (7) xvii. 1906, p. 434, and Flsli. Nile, p. 40, pi. ix. 

 fig. 2 (1907). 



Depth of body 3 to 3^ times in total length, length of head 4 to 

 4^ times. Head as long as deep; snout about \ length of head, 

 rounded, projecting beyond mouth ; mouth situated below nostrils, its 

 width about 4 times in length of head ; teeth bicuspid, 7 in upper jaw, 

 8 in lower ; anterior nostril on a line with centre of eye, midway 

 between latter and end of snout, posterior nostril a little lower down, 

 close to eye; eye moderate, as long as snout, -| to -| interocular width. 

 Dorsal 15-18, originating above 5th or 6th ray of anal, its length about 



Fig. 68. 



/; — "^"mm^^^ 







Marcuseiihis nigricans. 

 Type (F. ]N'.). |. 



I its distance from head. Anal 24-25, nearly equally distant from base 

 of ventral and from base of caudal. Pectoral pointed, subfalcate, as 

 long as or a little shorter than head, 2 to 2| times as long as ventral 

 and extending beyond root of latter. Caudal with pointed lobes. 

 Caudal peduncle 2^ to 2| times as long as deep, f to | length of head. 



in 1 1 • u J 10-12 • 



46-53 scales in lateral line, ^^^ in transverse series on body, i^iin m 

 transverse series between dorsal and anal, 16 to 20 round caudal 

 peduncle. Uniform blackish brown. 



Total length 93 millim. 



Lake Victoria. 

 1-9. Types. Mouth of Katonga E. Mr. E. Degen (C). 



15. MARCUSENIUS ISIDORI. 

 Mormjjrus isidori, Cuv. & Val. Hist. Poiss. xix. p. 285 (1846) ; Guuth. Cat. Fish. 



vi. p. 221 (1866), and Petherick's Trav. ii. p. 256 (1869). 

 Petrocephalus isidori, Marcusen, Bull. Ac. St. Petersb. xii. 1854, p. 14, and M6:n. 



Ac. St. Petersb. (7) vii. 1864, no. 4, p. 150, pi. v. fig. 20. 



