Classijicalioii of the Onhr ( Ksfan'ojil/fjs/. 21 



A. Ti'fth wt'U-developed in both jiiws, uniserirtl, fixed iucisors. 



Anostomu!>, lihytiodi<s, Luj)orinus, Leijoirllua. 



1>. Teeth very small, movable, labial, uniseiial in both jaws, or in 

 the npper only Canotrojnis. 



II. Month wide, non-protractile ; lips thin or absent; jaws toothless. 



I'ni'niaxillaiies expanded transversely, carrying' the small maxil- 

 . laries away from the mesethmoid ; rami of lower jaw moderately 

 lonp, their transverse anterior portions slender. .Snspensorium as 

 in the Anostominae. {Curimatmce.) . . Curimaius, Anudtts. 



III. Month terminal, somewhat protractile, with thick lips concealin^^- 

 the maxillaries; teeth minnte, labial. l*ra;maxillaries curved; 

 rami of lower jaw sliort, but formed as in tlie Curiniatinaj. 

 Quadrate movably articulated with the pteryjroid in front and the 

 pneopercle behind ; mesopterygoid and metapterygoid firmly 

 united by suture, but only loosely attached to the plery^^oid and 

 hyomandibnlar respectively (PI. II. Hg. 12) ; hyomandibnlar with 

 a single head, lilting into a groove formed by the sphenotic and 

 pterotic. {Pruc/i Hodontince. ) Prochilodus. 



Family 5. Hemiodontidoe. 



Prajniaxillaries small, movably attached to the ethmoid ; 

 maxillaries well developed, articulated vvitli or adherent to 

 the prjemaxillaries, their inner extremities articulating with 

 the mesethmoid ; mouth small, subterminal. Teeth uni- 

 serial, in both jaws or in the upper only ; palate toothless. 

 Pterygoid movably articulated with quadrate, narrowed 

 posteriorly, ending in a small condyle ; mesopterygoid firmly 

 attached to pterygoid and loosely connected with quadrate 

 (PI. II. fig. 4). In other osteological characters essentially 

 similar to the Characidee. Dorsal fin short, median ; anal 

 short ; scales cycloid ; lateral line, wh^n present, straight. 



South American. 



The principal genera may be arranged thus : — 



I. Teeth fixed, conical or cuspidate, forming a single series in both 



jaws. Hyomandibnlar broad, two-headed. {Nannosto mince.) 



Nannostvmus, Characidium. 



II. Frsemaxillaries with a single series of movable serrated incisors ; 



lower jaw with a rather sharp transverse toothless edge anteriorly, 

 with or without 2 or 3 small teeth laterally. Ilj'omaudibular with 

 a single head, fitting into a groove formed by the sphenotic and 

 pterotic. {^Hemiodo7itince.) .... Hemiodon, Saccodon, Parodoii. 



Family 6. Citharinidae. 



Upper jaw movable, the prsemaxillaries articulated with a 

 pair of antero-lateral apophyses of the mesetlinioid ; niaxil- 

 laiies articulated with or attached to prajtnaxillaries, their 

 inner ends not reaching the mesetiimoid. Teeth in jaws 



