Proceedings of 

 the United States 

 National Museum 



SMITHSONIAN INSTITUTION • WASHINGTON, D.C. 



Volume 116 



1964 



Number 3494 



A REVIEW OF THE OPHIDIOID FISH GENUS OLIGOPUS 



WITH THE DESCRIPTION OF A NEW SPECIES 



FROM WEST AFRICA 



By Daniel M. Cohen ^ 



Introduction 



This paper defines the genus Oligopus, presents a discussion of 

 generic synonymy, and gives diagnoses of six species, one of which is 

 described herein as new to science. 



The species of Oligopus have numerous fin rays and small scales, as 

 is true of many other ophidioids. Because the bases of the fin rays 

 almost invariably are obscured by darkly pigmented skin, most 

 counts of vertical fin elements were made from X-ray photographs. 

 In addition, internal skeletal characters were observed only from 

 X-ray photographs. Examination of the head pores was aided by 

 the use of a compressed air jet. 



These fishes secrete a thick mucous coat that often makes it difficult 

 to count scales and to observe pores. Also, the papillae that mark 



1 Director, Bureau of Commercial Fisheries Ichthyological Laboratory, Fish 

 and Wildlife Service. 



1 



