From Nichols & La Monte 1934:
Marcusenius maculipinnis, new species.
Specific Characters.—Anal originating in advance of dorsal. Teeth 7/7; 12 or 14 scales around caudal peduncle; lateral line, 55 to 66. Depth of body, 3 to 3.3 times in standard length; caudal peduncle 3 to 3.5 times as long as deep. Dorsal 17 or 18; anal 24 to 25. Caudal peduncle 1.1 to 1.3 in length of head. Front of dorsal and anal and base of caudal, each with a vague, blackish blotch.
Description of Type.—Number 12355, American Museum of Natural History; from Luluabourg, Kasai District, Belgian Congo; August 7, 1932; collected by Father R. Callewaert.
Length to base of caudal, 54 mm.; depth in this length, 3; head, 3.5. Eye in head, 4; snout, 6; interorbital, 3.7; width of mouth, 6; greatest width of body, 2.2; length of peduncle, 1.3; its depth, 5; pectoral, 1.2; ventral, 2.3; longest dorsal ray, 2; longest anal ray, 2; caudal lobe, 1.5. Dorsal rays, 17; anal, 24; scales, 55, about 12 or 14 around caudal peduncle.
Profile rounded with a blunt snout shorter than eye, projecting appreciably beyond the small mouth, the corners of which lie below the front of the eye. Dorsal origin slightly before the middle of the anal base, equidistant from pectoral origin and caudal base. Front of dorsal and anal moderately elevated.
Color dusky purplish, broken into small dark spots on the lower surface of head and belly, not appreciably paler below than above. Ill-defined dark blotches on the bases of the dorsal and anal in front and across the base of the caudal.
Three other specimens, 53 to 57 mm in standard length, were taken from the 8th to the 10th of August.
This species resembles M. adspersus of the Lower Congo but has fewer rays and more scales. It also suggests fasciaticeps Boulenger from Leopoldville, but has a relatively larger eye and shorter snout and a more uniformly dusky color.