A Bevision of South- American Gharacid Fishes. 387 



Family 15. Ilyophidae. 



Dorsal and anal continuous with the reduced caudal ; 

 pectorals present; body scaly ; vent remote from the head. 

 Mouth terminal, with lateral cleft extending behind the eye ; 

 maxillary slender, articulated with ethmoid near end of 

 snout J teeth conical, small and in narrow bands in the jaws, 

 large and in a single series on the vomer ; nostrils lateral; 

 gill-openings separate ; pharyngeal apertures of branchial 

 clefts wide. Suspensorium probably directed somewhat 

 obliquely backwards. 



Ilyophis hrunneus, Gilbert, may be related to the Anguil- 

 lidai on the one hand and the Synaphobranchidae on the 

 other, but it seems still nearer to the Dysommida?. 



Family 16. Dysommidae. 



External characters, jaws, and dentition of the Ilyophidse, 

 except that the body is naked, the vent is not far behind the 

 gill-openings, and the cleft of the mouth extends far 

 behind the eye. Frontals ankylosed to form a single bone ; 

 suspensorium directed very obliquely backwards ; palato- 

 pterygoid absent ; vertebral column as in the Anguillida3. 



Two genera, Dysomma, with pectoral fins and the vent 

 below the gill-openings, and Dysommopsis, without pectorals 

 and with the vent further back, have been described by 

 Alcock from the depths of the Indian Ocean. 



Family 17. Synaphobranchidae. 



External characters of the Ilyophidae, except that the cleft 

 of the mouth extends far behind the eye and the gill-openings 

 are confluent ; teeth small, conical, in narrow bands or in a 

 single series in jaws and on vomer. Frontals united to form 

 a single bone ; suspensorium long, directed very obliquely 

 backwards ; palato-pterygoid long, slender, almost vestigiaL 

 Vertebral column as in the Anguillidse* 



L. — A Revision of the South-American Gharacid Fishes of 

 the Genera Chalceus, Pyrrhulina, Copeina, and Pogono- 

 charax. By C. Tate Kegan, M.A. 



(Published by permission of the Trustees of the British Museum.) 



The four genera here dealt with form a natural group, 

 differing from other Characidse in the very large raesethnioid 



