2 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lie 



the course of the lateral line are fragile structures which may be 

 lost when the mucous coat is removed. 



Following are the definitions of some of the terms and abbreviations 

 used in this paper: Predorsal: shortest distance between tip of 

 snout and a vertical through origin of dorsal fin; preanal: shortest 

 distance between tip of snout and a vertical through origin of anal 

 fin; SL: standard length; HL: head length; upper jaw: shortest 

 distance between tip of snout and posterior margin of maxillary; 

 greatest depth of maxillary: depth at posterior expanded region of 

 bone, but not including downward projecting maxillary spine; greatest 

 head width: width of head with opercular flap compressed; D: dorsal 

 fin rays ; A: anal fin rays ; caudal fin rays: only those rays articulating 

 with hypural plate; vertebrae: count not including hypural; lateral 

 scale rows: counted from upper angle of opercle; head canals: ter- 

 minology follows Robins (1959). 



I have examined material deposited in the following institutions, 

 and I am much indebted to their respective curators: Academy of 

 Natural Sciences of Philadelphia (ANSP); British Museum (Natural 

 History) (BMNH); Museum of Comparative Zoology at Harvard 

 University (MCZ); Rhodes University, Grahamstown, South Africa 

 (RU); Scripps Institution of Oceanography (SIO); Stanford Uni- 

 versity, Division of Systematic Biology (SU); University of Bergen 

 Zoological Museum (UBZM); University of Copenhagen Zoological 

 Museum (UCZM); University of Hawaii (UH); U.S. National 

 Museum (USNM); University of Puerto Rico (UP). Mr. Luis 

 Rivas has furnished me with information concerning the type of 

 0. claudei. Mr. and Mrs. Craig Phillips have donated a specimen 

 of Stygnobrotula. Dr. Frank H. Talbot and Mr. W. I. Follett X-rayed 

 the type of Eutyx diagrammus. Mr. J0rgen Nielsen X-rayed the 

 type of Bythites juscus. Mr. Alwyne Wheeler X-rayed specimens 

 in the British Museum. I particularly thank my colleagues Dr. 

 Bruce B. Collette and Dr. Ernest A. Lachner for their advice during 

 the course of this study and for their critical review of the manuscript. 



Genus Oligopus Risso 



Oligopus Risso, 1810, p. 142 (type species by monotypy Oligopus ater Risso, 1810). 

 Gadopsis (not Agassiz, 1845; not Richardson, 1848) Filippi, 1856, p. 170 (type 



species by monotypy Oligopus ater Risso, 1810). 

 Grammonus Gill in Goode and Bean, 1896, p. 315 (type species by monotypy 



Oligopus ater Risso, 1810). 

 Verater Jordan, 1919a, p. 343 (proposed as a replacement name for Pteridium 



Filippi and Verany, 1859; however, these authors used Pteridium Scopoli, 



1777. Type species by original designation of Jordan Oligopus ater Risso). 

 Eutyx Heller and Snodgrass, 1903, p. 224 (type species by monotypy Eutyx 



diagrammus Heller and Snodgrass, 1903). 



