512 



Annals of the South African Museum. 



" Barely separable from Tilapia, differing only in the broader 

 bands of teeth in the jaws, showing when the mouth is closed, the 

 teeth being all very slender with expanded tricuspid crowns bent 

 inwards and disposed very regularly." (In a footnote Dr. Boulenger 

 points out that " as in Tilapia, the teeth are much more numerous 

 and form broader bands in the adults than in the young. Thus, in 

 P. tanganicae the transverse series vary with age from 5 to 12, the outer 

 series containing 58-100 teeth.") Vertebrae 31-82. 



Great Lakes of Africa. 



PBTBOCHBOMIS ANUEKSONII, Blgr. 



Bouleng., Ann. & Mag. Nat. Hist, (7), viii, 1901, p. 13, Fish, Nile, 

 p. 535, pi. xcvi (1907), and Freshw. Fish. Africa, iii, p. 269, 

 fig. 183 (1915) ; Pellegr. Mem. Soc, Zool. France, xvi, 1904, p. 351. 



FIG. 137. Pctrochromis andersonii. Type, f . 



Teeth in a broad band anteriorly, diminishing in width as it passes 

 backwards 011 the jaws. Depth of body 2-} times in total length 

 excluding caudal, length of head nearly 3 times. Head not quite 

 twice as long as broad ; snout as long as broad, 2-ij- times as long as 

 eye, which is six times in length of head and '2$ times in interorbital 



