MABCUSEN1US. 



75 



14. MARCUSENIUS NIGRICANS. 

 Bouleng. Ann. & Mag. N. H. (7) xvii. 1906, p. 434, and Fish. Nile, p. 40, pL 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. 58. 



Marcusenius nigricans. 



Type (F. N.), 



4" 



-§ 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 1\ times as long as ventral 

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

 Caudal peduncle 2\ to 2f times as long as deep, § to -f length of head. 



10-11 



10-12 

 10-11 



in 



46-53 scales in lateral line, jrrnj in transverse series on body, 

 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 R. Mr. E. Degen (C). 



15. MARCUSENIUS ISIDORI. 

 Mormyrus isidori, Cuv. & Val. Hist. Poiss. xix. p. 285 (1846) ; Giinth. 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 Mem. 



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



