498 cichlim:. 



two-thirds the length of the head. Anal fin with 3 spines and 6 to 8 soft rays ; third 

 spine as long as or a little longer than the last dorsal, about one-third to two-fifths the 

 length of the head. Pectoral fin rounded, three-fifths to two-thirds the length of the 

 head, not reaching the origin of the anal. Ventral fin rarely reaching the anal. 

 Caudal fin rounded. Caudal peduncle as long as deep. Scales rather strongly 

 denticulate, 25-29 1( J^q ; lateral lines ^j^, often represented merely by pits instead of 

 tubules. 



Specimens preserved in spirit are greyish or olive, with or without more or less 

 regular dark vertical bars and with or without an interrupted blackish stripe along the 

 side of the body ; a dark bar often extends from below the anterior third of the eye to 

 the mouth ; a black spot on the operculum and another at the root of the caudal fin ; 

 vertical fins with small dark spots ; soft dorsal and anal fins dark in the males, with 

 transverse series of white spots, which may be confluent into streaks ; males sometimes 

 with dark bars across the caudal fin. 



Sketches made by Mr. Loat represent the males as pale olive, with the scales edged 

 with bluish green, the dorsal, the anal, and the base of the caudal fin orange, with 

 transverse series of blue spots; the female greyish, with blue spots, and the fins 

 whitish. Iris orange. 



Mr. Schoeller thus describes the coloration of living specimens :■ — The back and 

 sides are of a light coppery violet, the lower parts whitish, all the scales very iridescent ; 

 older specimens tend more to a golden colour ; the dorsal fin is pale brownish yellow 

 with irregular rows of pale blue-green, strongly iridescent spots ; similar spots are also 

 found on the head and on the ventral and anal fins as well as on the base of the caudal 

 fin ; the yellow iris is traversed by a black streak and a red spot is present on its 

 anterior half. Males are more brilliantly coloured and distinguished by a red spot at 

 the end of the anal fin. During the nuptial period, a sky-blue sheen extends over the 

 males, the throat and ventral fins of which turn to deep black during the paroxysm of 

 excitement. When frightened or angry, the fish changes colour, becoming grey-green 

 with black longitudinal and transverse bars. 



This fish is one of the smallest of the Cichlidae, as it does not exceed a length of 

 70 millimetres. It resembles in general shape the young of Tilapia zillii, from which 

 it may be readily distinguished by the absence of the large ocellar spot on the anterior 

 part of the soft dorsal fin. 



As regards the variation in the fin-rays, I find, in eight specimens from Lake 

 Mareotis, Dorsal XIII 10 twice, XIV 9 twice, XIV 10 once, XV 8 twice, XV 9 once; 

 Anal III 6 twice, III 7 once, III 8 five times. In thirty specimens from the White 

 Nile, Dorsal XIII 9 six times, XIII 10 once, XIV 8 eight times, XIV 9 thirteen times, 

 XV 8 once, XV 9 once ; Anal III 6 three times, III 7 twenty-five times, and III 8 

 twice. 



