Freshwater Fishes from Madagascar. 423 
This genus is closely related to Pelmatochromis, Steind., 
from the Congo and West Africa ; as now restricted, Pelmato- 
chromis includes only species with few vertebra (25 to 27), 
short lower lateral line, and cycloid-scales (species 4 to 21 of 
Boulenger’s synopsis, with the addition of 5 placed in Para- 
tilapia, viz. P. cerasogaster, P. dorsalis, P. luebberti, P. 
corbali and P. thomasi). In Pelmatochromis the pharyngeal 
apophysis of the parasphenoid is not so strong as in Para- 
tz/apia and the inferior apophyses of the third vertebra unite 
to form a median spine, but other differences from Paratilapéa 
are unimportant, 
2. PTYCHOCHROMIS, Steind., 1880 (type Ti/apia oligacanthus, 
Bleek.). 
Dorsal XIJI-XV 10-14. Anal III 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 middle 
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-shaped articular surface for 
upper pharyngeals. Vertebre 28 (14414); third with 
inferior apophyses which unite below to form a median spine ; 
precaudals with parapophyses from the fourth ; ribs, except 
the first, on parapophyses. 
Madagascar ; two species. 
Related to Tylochromis, Regan, differing especially in 
having the teeth bicuspid instead of conical. Tylochromis 
occurs in West Africa, the Congo, and Tanganyika. 
3. Parerrop.us, Bleek., 1868 (type P. damii, Bleek.). 
Dorsal XVI-XX 11-18. Anal VII-X 9-14. A scaly 
sheath at base of dorsal and anal fins. Scales cycloid, large 
(32-37) ; two lateral lines. Mouth terminal ; end of max- 
illary exposed ; teeth in jaws uniserial, compressed aid some- 
what spatulate; one or two median pairs enlarged. Lower 
pharyngeals united by a sinuous suture to form a strong 
triangular plate ; most of the teeth stout, rounded, with flat 
surfaces. Occipital crest strong, extending forward to ante- 
rior end of frontals; parietal crests weak, ending above 
middle of orbits. Pharyngeal apophysis strong, formed by 
