TILAPIA. 519 



Pectoral tin nearly as long as the head, extending nearly to above the origin of the 



anal. Ventral fin extending beyond the origin of the anal. Caudal fin truncate. 



Caudal peduncle slightly longer than deep. Scales feebly denticulate, 31-32 ^ ; lateral 



v 21-22 

 lines ~ji-. 



Blackish or steel-grey above, somewhat lighter beneath ; seven ill-defined black bars 



on the body and a vertical black bar below the anterior third of the eye ; a black 



opercular spot; dorsal and ventral fins dark brown or black, the other fins dark 



greyish brown, the anal in one of the specimens with three orange ocellar spots ; 



iris white. 



Measurements (in millimetres). 



Total length 100 



„ „ (without caudal) 82 



Greatest depth of body 32 



Length of head 27 



Width of head 14 



Length of snout 7 



Diameter o eye 8 



Interorbital width 8 



Length of last dorsal spine 15 



,, longest soft dorsal ray 19 



„ third anal spine 15 



„ longest soft anal ray 18 



„ pectoral 2Q 



Lake Victoria. Described from two specimens in Mr. Degen's collection from 

 Entebbe (24.5.05), the larger caught with rod and line from the pier. 



5. TILAPIA ZILLIL 

 (Plate XCII.) 



Acerina zillii, Gervais, Ann. Sci. Nat. (3) x. 1848, p. 203. 



Coptodon zillii, Gervais, Bull. Soc. Agric. Herault, 1853, p. 80, pi. iv. figs. 5-7 ; A. Dume>il, Arch. 



Mus. x. 1859, p. 252. 

 Glyphisodon zillii, Valenciennes, C. R. Ac. Sci. xlvi. 1858, p. 713. 

 Haligenes tristrami, Giinther, Proc. Zool. Soc. 1859, p. 471, pi. ix. fig. B. 

 Chromis tristrami, part., Giinther, Cat. Fish. iv. p. 269 (1862). 

 Sarotherodon ? zillii, Giinther, t. c. p. 274. 

 Chromis andrece, Giinther, Proc. Zool. Soc. 1864, p. 492 ; Lortet, Ann. Mus. Lyon, iii. 1883, p. 142, 



pi. viii. fig. 3 5 Tristram, Faun. Palest, pi. xvii. fig. 1 (1884). 



