448 Mr. G. A. IJoulonger on 



less than |- lenfjth of head ; lonj^cst soft rays ? to | length 

 of head. Anal III 10-11 ; third spine ? to l length of 

 head. Pectoral once and ^ to once and ^ length of head, 

 extending to vertical of origin of anal or beyond. Ventral 

 reaching vent or not quite so far, rarely origin of anal. 

 Caudal trnncate, more or less obliquely in the adult, with the 

 lower angle rounded. Caudal pcdunf'le as long as deep or a 

 little longer than deep. Scales cycloid, 31-35 j^j^j^ ; lat. 1. 

 f?^. Coloration very variable, some specimens olive-brown, 

 others brilliant vermilion on the sides, others bright yellow 

 with black markings and the dorsal and caudal fins edged 

 with red, &c. The very young not distinguishable from 

 those of T. yaUhna and likewise with a blackish ocellar spot 

 on the anterior part of the soft dorsal. Iris grey or dai'k 

 hazel, with a red circle round the pupil. 



Numerous specimens, measuring from 20 to 3.20 ram., 

 from Entebbe, Bunjako, and Bnganga. 



Very closely allied to T. nilotica and T. galilcea, with which 

 species it has probably been coiifonndeil by other ichthyolo- 

 gists. Differs only in the smaller eye and the longer caudal 

 peduncle. 



Tilapia niyricans. 



Teeth small, in 6 series in both jaws, outer largest and 

 bicuspid, the others tricuspid. Depth of body 2^ to 2§ times 

 in total length, length of head 3 times. Upper profile of 

 head strongly curved ; snout broader than long, a little 

 shorter than the diameter of the eye, which is 3^ times in 

 length of head and equals interorbital width; mouth small, 

 with thick lips, not extending to below anterior border of 

 eye ; 3 series of scales on the cheek. Gill-rakers moderately 

 long, lOon lowerpartof anteriorareh. Dorsal XV-XVI 9-10; 

 spines equal from the eighth or ninth, nearly \ length of 

 head ; longest soft rays ;i to § length of head. Anal III 9 ; 

 third spine as long as longest dorsals. Pectoral nearly as 

 long as head, extending nearly to above origin of anal. 

 Ventr^il extending beyond origin of anal. Caudal truncate. 

 Caudal peduncle slightly longer than deep. Scales ctenoid, 

 31-32 Y^ ; lat. 1. ^"^-. Blackish or steel-grey above, some- 

 what 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 tins dark 

 brown or black ; other fins dark greyish brown, the anal in 



