A Revision of South- American Characid Fishes. 387 



Family 15. Ilyophidae. 



Dorsal and anal continuous witli the reduced caudal ; 

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

 Moutli terminal, with lateral cleft extending behind tlie eye ; 

 maxillary slender, articulated with ethmoid near end of 

 snout ; 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 b)-unneusj Gilbert, may be related to the Anguil- 

 lidaj on the one hand and the Synaphobranchidae on the 

 other, but it seems still nearer to tlie Dysommid^e. 



Family 16. Dysommidae. 



External characters, jaws, and dentition of the Ilyophidas, 

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

 gill-openings^ and the cleft of tlie mouth extends far 

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

 suspensorium directed very obliquely backwards ; ])alato- 

 pterygoid absent ; vertebral column as in the Anguillida?. 



Two genera, Di/somma, with pectoral fins and the vent 

 below the gill-openings, and Di/sommopsis, 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 Ilyophidfe, 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 Anauillidse. 



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

 the Genera Clialceus, Pyrrhulina, Copeiua, and Pogono- 

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



(PuUished by permissiou of tlie Trustees of the British Museum.) 



The four genera here dealt with form a natural group) 

 differing from other Characidse in the very large mesethmoid 



