10 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 56 



Distichodus notospihis Giinther. Kribi River, Cameroon {G. L. Bates) ; 

 Komadekke, Ogowe {W. J. Ansorge). 

 The Kribi R. specimen has the largest scales I have seen in this genus, 

 about 8.5 mm. long and 10.5 broad. 



Judging from the general characters of the fishes, and especially perhaps 

 from the development of the maxillary, we may infer that the Hydrocyoninse, 

 a carnivorous group, have given rise to the herbivorous Citharininas. Using 

 similar criteria, however, it would seem that the herbivorous Distichodontinse 

 had given rise to the carnivorous Ichthyoborinse. 



EXPLANATION OF PLATES 



Plate i. 



Fig. I. Scomber chrysoconiis. Massauah. British Museum. Gill rakers very 



long. 

 Fig. 2. Scomber pneiimatoplwriis. Table Bay, Cape of Good Hope. = colias 



= japoiiiciis. British Museum. 

 Fig. 3. Tilapia nilotica. Birket Karun, Fayoum. British Museum. 

 Fig. 4. Alestes sadleri. Entebbe. Lake Victoria (Degen). British Museum. 

 Fig. 5. Micralestes holargyreus Giinther. Boma (Delhez). British Museum. 

 Fig. 6. Petersius candaUs. Boma (Delhez). British Museum. 



Plate 2. 



Fig. i. Citharidium ansorgii. Lake Oguta. S. Nigeria (Ansorge). British 

 Museum. 



Fig. 2. Citharinus congiciis. Bololo. Congo (GrenfelJ). British Museum. 



Fig. 3. Engnathichthys cetveldii Blgr. Monsembe. Upper Congo (J. H. 

 Weeks). British Museum. 



Fig. 4. Xenochara.v spUtirus. Ibali. Lake Leopold II (Delhez). British 

 Museum. 



Fig. 5. Distichodus aiitonii. Monsembe. Upper Congo (Weeks). British 

 Museum. 



Fig. 6. Distichodus scxfasciatiis. Coquilhatville. Upper Congo (Delhez). 

 British Museum. 



Fig. 7. Distichodus notospilus. Komadekke. Ogowe (W. J. Ansorge). Brit- 

 ish Museum. 



