GNATHONEMTJS. 53 



devour the finely chopped-up earthworms on which they are fed daily. They usually 



keep moving about the bottom of the tank, the pectoral and tail fins being almost 

 constantly in motion, the other fins being only occasionally used." 



3. GNATHONEMUS MACROLEPIDOTUS. 

 (Plate X. fig. 1.) 



Mormyrus macrolepidotus, Peters, Mon. Berl. Ac. 1852, p. 275, and Reise Mossamb. iv. p. 79, pi. xv. 



fig. 1 (1868). 

 Mormyrops macrolepidotus, Marcusen, Mem. Ac. St. Petersb. (7) vii. 1864, no. 4, p. 142. 

 Gnathonemus macrolepidotus, Boulenger, Proc. Zool. Soc. 1898, p. 804, and Poiss. Bass. Congo, p. 93 



(1901); Pellegrin, Mem. Soc. Zool. France, xvii. 1905, p. 181. 



Body strongly compressed, its depth three and a half to four times in the total 

 length ; length of head four and a half to five times in the total length. Head nearly as 

 long as deep, one-half or a little more than one-half as broad as long, with curved upper 

 profile; snout short, rounded, about one-fourth the length of the head, and once 

 (young) to once and a half the diameter of the eye ; interorbital width once and a half 

 to once and two-thirds the diameter of the eye ; mouth small, on a line with the lower 

 border of the eye; chin projecting, with a globular dermal appendage; teeth small, 

 conical, 3 or 5 in the upper jaw, 6 in the lower. Dorsal fin with 23 to 25 rays, 

 originating above the seventh or eighth ray of the anal, its length about twice and 

 a half in its distance from the head. Anal fin with 28 to 32 rays, a little nearer the 

 base of the caudal than that of the ventral. Both fins deepest in front. Pectoral fin 

 pointed, shorter than the head, reaching the base of the ventral or a little beyond. 

 Caudal fin scaly in its basal half, with obtusely pointed lobes. Caudal peduncle 

 nearly as long as the head, twice and a half to three times as long as deep. 56 to 69 

 scales in the lateral line, y^$ in a transverse series on the body, g^ ^ n a transverse 

 series between dorsal and anal fins, 12 to 16 round caudal peduncle. 



Coloration as in 0. cyprinoides, the young also frequently with irregular small dark 

 spots on the body. 



The species reaches a length of 320 millim. 



Inhabits the Zambesi, the Katanga, Lake Bangwelo, and the Eovuma River. 



The specimen from Kavirondo Bay, Lake Victoria, determined as G. macrolepidotus 

 by Pellegrin, and which Prof. Vaillant has been so good as to entrust to me for study, 

 may be regarded as forming a connecting-link between this species and G. cyprinoides. 

 As may be seen from the subjoined table, the scales of this young specimen, measuring 

 only 96 millim., are considerably smaller (more numerous) than in the Bangwelo and 

 Zambesi specimens at my disposal. I therefore regard Pellegrin's determination as 

 provisional, and I am inclined to think that the study of a larger material from 



