TILAPIA. 213 



extending to between nostril and eye ; teeth in outer row rather large, 

 36 in upper jaw, with an inner row of very minute teeth ; 6 series of 

 scales on the cheek, width of scaly part equal to diameter of eye. Gill- 

 rakers very short, 12 on lower part of anterior arch. Dorsal XV 13; 

 spines equal in length from the seventh, which is f length of head ; 

 longest soft rays | length of head. Anal III 9 ; third spine nearly as 

 long as longest dorsal. Pectoral § length of head, not reaching vertical 

 of origin of anal. Ventral barely reaching vent. Caudal rounded. 

 Caudal peduncle as long as deep. Scales with feebly denticulated 

 border, 34 ^ ; lateral lines 7^. Brownish above, yellowish beneath ; 

 dorsal with round black spots between the soft rays. 



Total length 110 millim. 



Lake Ngami Basin. 

 1. Type. Okovango R. I\. 15. Woosnam, Esq. M .). 



-17. TILAPIA JALLJS. 



Chromis jallce, Bouleng. Boll. Mas. Torin. xi. 1896, p. 260. 



Tilapia jallce, Bouleng. Proc. Zool. Soe. 189!), p. 123 ; Pellegr. Mem. Soc. Zool. 

 France, xvi. 1904, p. 329. 



Depth of body 3-^ times in total length, length of head 3£ times. 

 Snout a little longer than eye, which is 3^ times in length of head and 

 ]-| times interorbital width ; mouth not extending to below anterior 

 border of eye ; teeth small ; 6 or 7 series of scales on the cheek. Gill- 

 rakers short, 9 on lower part of anterior arch. Dorsal XV 10; spines 

 subequal from the fifth, which measures ^ length of head ; last soft 

 rays prolonged into filaments. Anal 111 8 ; third spine as long as 

 longest dorsal. Pectoral § length of head. Caudal truncate. Caudal 



3 . 21 



peduncle 1^ times as long as deep. Scales cycloid, 33 g - ; lateral lines ^- 

 Olive-brown, with traces of five darker bars. 



Total length 75 millim. 



Upper Zambesi (district of the Victoria Falls). — Type in Turin 

 Museum. 



48. TILAPIA HUMILIS. 



Chromis humilis, Steind. Verh. zool.-bot. Ges. Wien, xvi. 1866, p. 763. 

 Tilapia humilis, Bouleng. Proc. Zool. Soc. 1899, p. 124 ; Pellegr. Mem. Soc. Zool. 

 France, xvi. 1904, p. 322. 



Depth of body 3f times in total length, length of head 3^ times. 



