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TRANSACTIONS OF THE AMERICAN PHILOSOPHICAL SOCIETY 



Ridewood's thorough studies indicate that the notopterids, while constituting a 

 specialized side branch, have come off from near the stem of the mormyrids. On the other 

 hand Frost (1925, p. 160) has shown that in Nolopterus kapirat the very peculiar swollen 

 otolith with a styliform rostrum is very unlike those of the typical clupeoids but might 

 be derived from a type similar to that of Gonostoma denudatum. 



Mormyrids. — The mormyrids of tropical Africa are well known for their remarkable 

 and peculiar specializations. The least specialized mormyrid skull is that of Mormyrops 



JOC 



pm^ 



Mormyrops deliciosus 



Fig. 62. A. Mormyrops deliciosus. B. Gymnarchus nilolicus. After Hyrtl. 



