TILAPIA. 



203 



pneorbital depth ; mouth about f width of head, extending to between 

 nostril and eye ; teeth in 4 or 5 series, outer largest, 60 to 70 in upper 

 jaw, and separated from the others by a rather wide interspace; 3 or 4 

 series of scales on the cheek, width of scaly part not greater than diameter 

 of eye. Gill-rakers short, 10 on lower part of anterior arch. Dorsal 

 XV-XVI 8-10 ; last spine longest, | length of head ; longest soft rays 



Fig. 129. 



Jut 



Tilapia tliolloni. 

 Type. |. 



nearly as long as head. Anal III 8-9 ; third spine a little shorter than 

 last dorsal. Pectoral as long as head, reaching vertical of origin of anal, 

 or not quite so far. Ventral not reaching anal. Caudal rounded, 

 scaled nearly all over. Caudal peduncle as long as deep or a little 



q 19-21 



deeper than long. Scales cycloid, 29-30 y[Z{2 ; lateral lines g-jo . Olive ; 

 a black opercular spot continued as a more or less interrupted dark 

 band along the side of the body ; rather indistinct dark cross-bars may 

 be present on the body ; dorsal with dark and light streaks and a 

 blackish spot at the base of the origin of the soft dorsal ; caudal with 

 round light spots in a dark network. 



Total length 180 millim. 



Upper Ogowe, Chiloango, Lower Congo — Types in Paris Museum. 



1. Ad. Kalombo-Songo Lagoon, Chiloango R. Major Cabra (C). 



2. Ad. Boma, Lower Congo. Mr. J. Paul Arnold (P.). 



