518 cichlid^. 



Gill-rakers short, 8 or 9 on lower part of anterior arch. Dorsal fin with 15 or 16 

 spines and 8 to 10 soft rays ; spines increasing in length to the last or last few, 

 two-fifths to half the length of the head ; longest soft rays half to four-fifths the 

 length of the head. Anal fin with 3 spines and 8 to 10 soft rays; third spine as 

 long as longest dorsal. Pectoral fin three-fourths to once the length of the head, 

 extending to the vertical of the origin of the anal or a little beyond. Ventral fin 

 extending to the origin of the anal or beyond. Caudal fin rounded. Caudal peduncle 

 once and one-fourth to twice as long as deep. Scales strongly denticulate, 29-33 jf^; 

 lateral lines grjj. 



Adult males black, the anal fin and the border of the caudal fin often bright 

 vermilion ; orange ocellar spots sometimes present on the anal. Females and young 

 dark grey or brown to blackish, with or without black bars on the body; usually a 

 black vertical bar below the anterior third of the eye ; a black opercular spot ; dorsal 

 and anal fins dark grey or brown, edged with black ; caudal fin grey or brown, and, 

 like the soft dorsal, with more or less distinct small darker spots ; ventral fins greyish 

 or yellow. 



Lake Victoria. About forty specimens were obtained by Mr. Degen at Entebbe, 

 21.6~11.10.05. 



This species is very closely allied to the preceding, differing principally in the shape 

 of the caudal fin. 



4. TILAPIA NIGRICANS. 



(Plate XCL fig. 5.) 



Boulenger, Ann. & Mag. N. H. (7) xvii. 1906, p. 448. 



Depth of body twice and a half to twice and two-thirds in the total length, length 

 of head three times. Upper profile of head strongly curved ; snout broader than long, 

 a little shorter than the diameter of the eye, which is three and one-fourth times in 

 the length of the head, equals the interorbital width, and much exceeds the least 

 width of the prseorbital; mouth small, with thick lips, not extending to below the 

 anterior border of the eye ; teeth small, in six series in both jaws, outer largest and 

 numbering 44 to 50 in the upper jaw; three series of scales on the cheek, the depth 

 of the scaly part a little less than the diameter of the eye ; large scales on the opercle. 

 Gill-rakers moderately long, 10 on lower part of anterior arch. Dorsal fin with 15 or 

 16 spines and 9 or 10 soft rays; spines equal from the eighth or ninth, nearly half 

 the length of the head; longest soft rays three-fifths to two-thirds the length of the 

 head. Anal fin with 3 spines and 9 soft rays ; third spine as long as longest dorsals. 



