208 



THE TANGANYIKA PROBLEM. 



the longest dorsals. Caudal with deep crescendo notch. Caudal peduncle twice as 



10 

 long as deep. Scales cycloid, 80-90 ; lat. 



46 — 49 

 1 „ . Pale olive-brown 

 38—42 



29—30 



above, white below ; faint dark bars across the back and four round dark spots 

 on each side, the last at the root of the caudal ; fins yellowish. 

 Total length, 115 millim. 



Described from two specimens. Native name, " Mocupi." 



As in Tilapia desfontainesi, the dentition of this species may be regarded as 

 connecting Tilapia with Paratilapia. 



78. Petrochromis polyodon. — Blgr. 1! 



(Fig. p. 197.) 



Crowns of teeth brown. Depth of body 2.1 to 2§ times in total length, length of 

 head 2% to 3 times. Snout, with convex upper profile, ih to i| diameter of eye, 



Barilius moorii. See p. 158. 



which is 4 to 4.T times in length of head andi h ininterorbital width ; mouth hardly 

 extending to below anterior border of eye ; 4 or 5 series of scales on the cheek ; 

 large scales on the opercle. Gill-rakers very short, 12 or 13 on lower part of 

 anterior arch. Dorsal XVII. -XVIII. 8-9 ; spines increasing in length to the sixth 

 or seventh, which measures about § length of head ; longest soft rays J to 5 length of 

 head Pectoral nearly as long as head. Ventral reaching vent or origin of anal. 



