1906.] 



NATURAL SCIENCES OF PHILADELPHIA. 



CYNOCHARAX subgen. nov. 

 Type Anacyrtus afflnis Gunther. 



457 



For those species with well-developed canines in the upper jaw. 

 (Kuwv, dog; jirayoa*', Charax.) 

 Eoeboides affinis (Gunther). Fig. 46. 



Rceboides ruhrivertex Cope, Proc. Acad. Nat. Sci. Phila., 1871 (1872), p. 265. 

 Type, No. 8,190, A. N. S. P. Between the mouth of the Peruvian 

 Amazon or Ucayale river. Robert Perkins. Cope, I.e., p. 292. 



Width of head 2 in its length ; interorbital space 3. Body compressed 

 strongly and edges of back rounded. Preventral region rather broad 

 and flattened. Postventral region with a slight median keel or some- 

 what trenchant. Head well compressed. Snout broadly convex, 



M 



^-*^i^ 



Fig. 46. — Rceboides afjinis (Gunther). 



much broader than deep. Upper jaw with 6 external teeth, and 1 

 on outside near base of each maxillary. Mandible with 4 external 

 teeth. Upper jaw with 2 series of teeth of about equal size, posterior 

 not confluent anteriorly. Mandibular teeth uniserial, with 4 canines, 

 pair at symphysis close together. Maxillary with upper | of its edge 

 finely denticulated. No palatine teeth. Tongue fleshy, triangular 

 and free. Interorbital space convex. Gill-opening forward about 



