HAPLOCHROMIS 495 



5. HAPLOCHROMIS. 



Hilgendorf, Sitzb. Ges. naturf. Fr. Berlin, 1888, p. 76. 



Ctenochromis, Pfeffer, Jahrb. Hamb. Wiss. Anst. x. 1893, p. 149, and Thierw. O.-Afr., Fische, 



p. 14 (1896). 

 Tilapia, part., Boulenger, Proc. Zool. Soc. 1899, p. 105, and Poiss. Bass. Congo, p. 452 (1901). 

 Astatotilapia, Pellegrin, Mem. Soc. Zool. France, xvi. 1904, p. 299. 

 Astatoreochromis, Pellegrin, t. c. p. 384. 



Teeth in two or more series, the outer conical or bicuspid, the inner usually 

 tricuspid. Maxillary bone exposed at the end when the mouth is closed. Body short 

 or moderately elongate; scales ctenoid; two lateral lines. Dorsal fin with 13 to 19 

 spines, anal with 3 to 6. 



The vertebra? number 30 or 31, 15 + 16 in II. desfontainesi, 14 + 16 in //. alluaudi, 

 14+17 in H. ishmaeli. 



Africa and Syria. About 10 species are known, 7 of which are here described. 



The fishes of this genus are very perplexing in the variations of characters which 

 have usually been regarded as of generic importance, such as the shape of the teeth 

 and the number of anal spines. This state of things has given rise to much synonymy, 

 and individuals of the same species have been referred to two genera. The outer 

 teeth are always bicuspid and the inner tricuspid in young specimens, and often also 

 in females, whilst the outer, and sometimes even the inner, are unicuspid in adult 

 males, which, in the absence of series of specimens, would be referred to Paratilapia. 

 The specimens with bicuspid outer teeth may be distinguished from Tilapia in 

 having the maxillary bone exposed when the mouth is closed, as in Paratilapia. 



Synopsis of the Species. 



I. Teeth in two to four series ; pectoral fin usually shorter than head. 



A. Caudal fin truncate ; caudal peduncle once and a half as long as deep ; depth of body 



more than three times in total length. 



D. XIV-XV10; A. Ill 9; Sq. 32^ 1. II percoides, Blgr. 



B. Caudal fin rounded ; caudal peduncle not or but slightly longer than deep ; depth of body 



not more than three times in total length. 



L>. XIII-XV 8-10 ; A. Ill 6-8 ; Sq. 25-29 ^ 2. H. strigigena, Pfeff. 



D. XIH-XVI 8-12 ; A. IH-IV 8-11 ; Sq. 28-36 ^ .... 3. II desfontainesi, Lacep. 



D. XVIII-XIX 7-8; A. IV-YI 6-9 ; Sq. 32-34 £1 . . . . 4. H> alluaudi, Pellegr. 



