134 CICHLID^. 



Fresh or brackish waters of Africa, Syria, India and Ceylon, and 

 America. Mostly from Tropical Africa and Tropical America. 



The classification of the very numerous African members of this 

 family presents the greatest difficulties, and the division into genera, as 

 here followed, is unsatisfactory and open to criticism, the dentition in 

 certain species being subject to variation, according to age, or even of a 

 purely individual nature. This has to be borne in mind in making use 

 of the following Synopsis. I have also been compelled to abandon the 

 hope I entertained (Poiss. Bass. Congo, p. 393) of basing a more natural 

 classification on the number of prsecaudal vertebrae as compared to that 

 of the caudals. 



Sgiiojisis of the Genera. 



I. Dorsal and anal fins without scaly sheath at the base. 



A. Outer teeth hi- or tricuspid, rarely conical *, without canines in front, not 

 swollen at the base. 

 Teeth forming narrow or moderately broad 



bands, the outer bicuspid, rarely conical ; 



dorsal with 11—19 spines, anal with 3 or i. 1. Tilapiq, A. Smith, p. 138. 

 Teeth forming very broad bands, all tricuspid ; 



dorsal with 16—20 spines, anal with 3 . . 2. Petrochromis, Blgr., p. 267. 

 Teeth forming very broad bands, all tricuspid ; 



dorsal with 13 spines, anal with 3 . . . 3. Cunningionia, Blgr., p. 273. 

 Teeth forming broad bands, those of the outer 



series bicuspid in front, conical, enlarged, 



and sharply differentiated on the sides of 



the prsemaxillaries ; dorsal with 17-]',) 



spines, anal with 3 4. Simocliroyiis, Blgr., p. 271. 



Teeth forming broad bands in front, those of 



the outer scries bicuspid ; sides of prse- 



jnaxillaries with a single series of conical, 



enlarged, and sharply differentiated teeth ; 



dorsal with 20-21 spines, anal with 4-6 . 5. Tropheus, Blgr., p. 276. 

 Mouth inferior, with two series of small tri- 

 cuspid teeth ; body much attenuate in the 



caudal region ; dorsal with 14 spines, anal 



with 3 6. Asprotilapia, Blgr., p. 278. 



* Tilapia, species mentioned in footnote, p. 138. See also Divisions C and D of this 

 Synopsis. 



