CYPRINID^. 57 



tt. Rudimentary dorsal ray attached : 

 d. Teeth not molar, in one or two rows : 

 e. Maxillary without barbel : 

 /. Teeth in the principal row 4-4 : 



g. Alimentary canal olonirato, about four times length of body ; teeth one- 

 rowed, cultriform, with oblique grinding surface and little or 

 no hook; premaxillary projectile; lips attenuate, witliout 

 sheath ; scales large : 

 h. Lateral line almost wanting; mouth oblique ; dorsal in front of ven- 



trals Couscus, 5. 



hh. Lateral line complete; mouth horizontal; dorsal over ventrals: 

 — . Teeth elongate with narrow grinding surface and no hook ; body 



elongate Hybogxatiius, 6. 



. Teeth short, with rather broad grinding surface and slight hook ; 



body short and rather stout; size small Dionda, 7. 



gg. Alimentary canal short, about as long as body ; teeth raptatorial, 

 usually strongly hooked : 

 i. Teeth with grinding surface developed, not crenate : 

 j. Dorsal fin beginning above ventrals (i. e., above some part of base 

 of ventrals) ; anal basis short : 

 — . Scales small, much longer than deep, with much of the surface ex- 

 posed; body stout, compressed; teeth one-rowed, little hooked, 

 the uppermost standing out above the surface of the bone; 



size large (Subgenus?) Algansea,* 8. 



. Scales large, about as long as deep, the usual surface exposed ; 



teeth one- or two-rowed, pretty strongly hooked ; size usually 



quite small (Subgenus ?) H vnopsis, 9. 



. Scales large, much deeper than long on the sides, the ex- 

 posed surfaces very narrow ; teeth one or two-rowed, strongly 



hooked; size moderate or large LuxiLUS, 10. 



jj. Dorsal fin beginning entirely behind ventrals, between ventrals 



and anal ; anal basis elongate Lytiirukus, 11. 



ii. Teeth with the edges creuate; dorsal fin beginning over middle or 

 last rays of ventrals ; scales closely and smoothly imbricated; 

 teeth one-rowed {Montana) or two-rowed {CyprineUa), 



CVPIUXELLA, 12. 



Hi. Teeth with edges entire and without grinding surface : 

 h. Lips thin, normal ; lateral line complete : 

 I. Species of small size and weak organization, with the mouth little 

 cleft : 

 m. Scales comparatively thick, closely and smoothly imbricated, 

 so that the exposed surfaces are higher than long; dorsal fin 

 beginning opposite between first and last ray of ventrals, rarely 

 slightly posterior; mouth subinferior, somewhat oblique; 

 males in spring developing a satin-white pigment in the tips 

 of the vertical fins and in the skin of the abdomen ; snout 

 tuberculate; colors brilliant, pigmented, 



(Sul)genus?) Photogenis, 13. 

 mm. Scales thin, much exposed ; no white satiny pigment (except 



in Codomaf): 



* In A. tincella, the type of Algansea {Leudmis lincdla C. T. V., Hist. Nat. des Poissous 

 xvii, 323), the teeth are said to be 4-4. In some species referred to Algansea, they are 

 5-5. These I refer for the present to Mylolcmus, from the type of which genus they 

 differ in having but one row of teeth. 



