TILAPIA. 



225 



brown longitudinal band in its upper portion ; male with the mouth 

 and ventrals blackish (dark blue in life), and a few large bright ocellar 

 spots on the anal. 



Total length 115 millim. 



Angola. 



1-2. Types. 

 3. Skel. 



Luculla R. at Luculla. 



Dr. W. J. Ansorge (C.). 



59. TILAPIA WILLIAMSII. 

 Chromis williamsi, Giintli. Proc. Zool. Soc. 1893, p. 621, pi. Ivi. fio-. C. 

 Tilapia williamsi, Bouleng. Tr. Zool. Soc. xv. 1898, p. 4, and Proc. Zool. Soc. 

 1899, p. 132 ; Pellegr. Mem. Soc. Zool. France, xv. 1904, p. 335. 

 Depth of body equal to length of head, 3 times in total length. Head 

 twice as long as broad ; snout broadly rounded, with slightly convex 

 \ipper profile, broader than long, much shorter than postocular part of 



Fi<?. 147. 



Tilapia ivilliainsii. 

 Type, after Giinther (P. Z. S. 1893). 



head ; eye a little shorter than snout, 4 times in length of head, a little 

 less than interorbital width, equal to least depth of prseorbital ; mouth 

 broad, J width of head, with thick lips, extending to below anterior 

 border of eje; teeth in 5 or 6 series, outer larger; in the upper jaw 

 the lateral teeth are conical and rather abruptly differentiated from the 

 others, which are bicuspid ; 52 teeth in outer series of upper jaw ; 

 4 series of scales on the cheek, width of scaly part equal to diameter of 

 eye. Gill-rakers short, 10 on lower part of anterior arch. Dorsal 

 XVII 8 ; last spine longest, nearly J length of head, | longest soft rays. 

 Anal III 7 ; third spine a little shorter than last dorsal. Pectoral f 

 length of head, not extending to origin of anal. Ventral reaching vent. 

 VOL. Ill, Q 



