148 SMITHSONIAN MISCELLANEOUS COLLECTIONS [voL. 45 



18. PIARACTUS 

 New genus of Mylesinse, allied to Myleus and Colossoma. 



Premaxillary teeth with an oblique cutting edge, in two series. 

 No procumbent predorsal spine ; adipose fin rayed ; free margin of 

 .anal convex, without lobes. 



Type. — Myletes brachypomus Cuv. 



map, fat; dxrc^, a ray. 



19. ORTHOMYLEUS 

 New subgenus of Myleus. 



Differing from typical Myleus in having the dorsal rays not pro- 

 longed into filaments. 



Type. — Myletes elliptictis Giinther. 

 opdoQ, straight; Myleus. 



20. COLOSSOMA Eigenmann & Kennedy- 

 New genus of Mylesinge, allied to Myleus. 



Premaxillary teeth with an oblique cutting edge, in two series. 

 No procumbent predorsal spine ; adipose dorsal not rayed ; anal 

 naked, its margin straight or convex. 



Type. — Myletes oculus Cope. 



xoloi;, without horns (predorsal) ; a 10 pa, body. 



21. MYLOSSOMA Eigenmann & Kennedy. 

 New genus of Mylesinse, allied to Myleus. 



As in Colossoma but with the anal scaled, its margin convex, with- 

 out lobes, the rays of the posterior third longest. Gill-rakers rather 

 long, numerous. 



Type. — Myletes albiscopus Cope. 



fjiuXo^, a millstone; (Tcoim, body. 



