The Freshwater Fishes of South Africa. 477 



A very strong papillose pad in front of the 



gill arches ; otherwise as in Pa ratilapia . Pelmatochromis,Stndr. 

 Teeth in one or two, very rarely three series, 



the two median teeth of the outer series 



enlarged ; dorsal with 13-15 spines . . Hemichromis, Peters. 



TILAPIA. 



Chromis, part., Cuvier, Regne Anim., ii, p. 266 (1817); Griinth., 

 Cat. Fish, iv, p. 267 (1862). 



Tilapia, A. Smith, 111. Zool. S. Afr. Fish. (1849) ; Bouleug., Proc. 

 Zool. Soc., 1899, p. 105, part, ; Poiss. Bass. Congo, p. 452 (1901), Fish. 

 Nile, p. 513 (1907), and Freshw. Fish. Africa, iii, p. 138 (1915) ; 

 Pellegr., Mcni. Soc. Zool. France, xvi, 1904, p. 307. 



Sarotherodon, Riipp., Verz. Mus. Senck., iv, p. 21 (1852) ; Griinth., 

 t.c., p. 273. 



Goptodon, G-ervais, Bull. Soc. Agric. Ht-rault, 1853, p. 81. 



Halifjenes, Gunth., Proc. Zool. Soc., 1859, p. 471. 



Ptychochromis, Steiudr., Sitzb. Ak. Wien, Ixxxii, i, 1880, p. 248 ; 

 Pellegr., t.c., p. 346. 



Oreochromis, Giiuth., Proc. Zool. Soc, 1889, p. 70; Pellegr., t.c., 

 p. 354. 



Ctenochromis, part., Pfeff., Jahrb. Hamb. Wiss. Anst., x, 1893, 

 p. 149. 



Oplithalmotilapia, Pellegr., t.c., p. 345. 



" Body short or more or less elongate ; scales cycloid or ctenoid ; 

 two incomplete lateral lines. Teeth in t\vo or more series, the outer 

 bicuspid,* the others tricuspid ; maxillary usually more or less com- 

 pletely hidden under the praeorbital when the mouth is closed. 

 Dorsal fin with 1 1-19 spines, anal with 3 or 4. Parietal and occipital 

 crests strong, extending to between the orbits. Vertebrae 26-34." 



Synopsis of the South African Species described. 



I. Scales cycloid (rarely indistinctly ctenoid). 



A. Gill-rakers 15-27 on lower part of anterior arch. 



Anal spines 3 (very rarely 4) ; pectoral usually as long as or longer 



than head, often reaching vertical of origin of anal or beyond. 

 Caudal not densely scaled. 



1. Outer teeth small and slender or unicuspid. 



* " Occasionally conical or indistinctly biscuspid in a few species which are 

 related to T. nilotica (T. nigra. mossambica, natalensis, linnelli, squamipinnis) 

 See also Haplochromis." 



