■ FreshiCdter Fishes from Madagascar. 423 



This genus is closoly icliited tt) Pehiiatochromis, .Steiiul., 

 from the Congo and West Africa ; as now lestricted, Felmato- 

 chvomis includes only species with few vertebrai (25 to 27), 

 short lower lateral line, and cycloid scales (species 4 to 21 of 

 B. ulenger's synopsis, with the addition of 5 plact-d in Para- 

 tila/>ia, viz., P. cerasogaster, P. dorsahs^ P. luebberti, P. 

 corb(di and P. thomad). In Pelmatochromis the pharyngeal 

 a[)ophysis of the parasphenoid is not so strong as iti Para- 

 tilapia and the inferior apophyses of the third vertebra unite 

 to form a median spine, but other differences from Paratilapia 

 are unimportant. 



2. Ptychochromis, Steind.,1880 (type Tilapiaoligacanthus, 



Bleek.). 



Dorsal XIII-XV 10-14. Anal ITI 7-12. Scales finely 

 denticulate, large (32-36) ; two lateral lines. Mouth ter- 

 minal ; end of maxillary exposed ; teeth in jaws compressed, 

 bicuspid, in 3 to 5 series, outermost enlarged, inner small. 

 Lower pharyngeals united by a sinuous suture to form a 

 triangular plate, with large rounded blunt teeth in the a)iddle 

 posteriorly and slender bicuspid teeth elsewhere. Occipital 

 and parietal crests extending forwards to above middle of 

 orbits ; former high, ending behind a median depression on 

 frontals. Posterior part of parasphenoid forming a strong 

 apophysis with flattish heart-sha[)ed articular surface for 

 upper pharyngeals. Vertebrae 28 (14 + 14); third with 

 inferior apophyses which unite below to form a median spine ; 

 pracaudals with parapophyses from the fourth ; ribs, except 

 the first, on parapophyses. 



Madagascar ; two species. 



llelated to Ti/Ioch-vmisy Regan, differing especially in 

 having the teeth bicuspid instead of conical. Tglochromis 

 occurs in West Africa, the Congo, and Tanganyika. 



3. Paretroplus, Bleek., 1868 (type P. damii, Bleek.). 



Dorsal XVI-XX 11-18. Anal VII-X 9-14. A scaly 

 sheath at Ijase of tiorsal and anal (ins. Scales cycloid, laroe 

 (32-37) ; two lateral lines. Mouth terminal ; end of max- 

 illary exposed; teeth in jaws uniserial, comj)ressed ai.d sonie- 

 what spatulate ; one or two meilian pairs enlarged. Lower 

 pharyngeals united by a sinuous suture to forn) a strong 

 triangular j)late ; most of the teeth stout, rounded, with flat 

 suifaces. Occipital crest strong, extending forward to ante- 

 rior end of frontals ; parietal crests weak, ending above 

 middle of orbits. Pharyngeal apt)physis strong, formed by 



