eigenmann: eresh water eishes. 255 



qq. No adipose ; dorsal over anal, higher than long ; anal 



long (20-31). XVI. Stevardiina;,'YnmA2i6.. 



pp. Opercle not prolonged ; usually a single series of teeth in 



the lower jaw, some genera imperfectly with two series. 



XVII. Tetragonopteritice , American and African. 



kk. Skull without fontanels ; mandible with two series of teeth. 



r. An adipose dorsal ; walls of the air-bladder not cellular. 



XVIII. PiabiicinincB, American. 



;-;'. No adipose fin ; walls of the anterior portion of the posterior air 



bladder cellular ; premaxillary, maxillary, and outer series of the 



teeth of the dentary tricuspid. 



XIX. LebiasinincE, Pacific slope of Peru to Colombia. 



a. Belly compressed before the ventrals ; no ventral spines; intestine short ; gill-rakers 



moderate ; nares close together. 



s. Pectorals large, nearly or quite reaching anal, placed high or moderately so ; 



gill -membranes free ; breast more or less expanded. 



XX. GasteropelicincE, American. 

 ss. Pectoral small, placed low. 



t. Body elongate ; anal basis nearly horizontal. 



XXI. Agoniatince, American. 

 tt. Body deep ; anal basis very oblique ; mouth very oblique ; pectorals on a 

 level with or below the level of the lower margin of the preopercle. 



XXII. StethaptionincB, American. 

 in. Belly trenchant and serrate, at least behind the ventrals ; intestine short ; body com- 

 pressed and deep. 

 u. All teeth in the jaws in a single series, trenchant or serrate ; gill-rakers mostly 

 short. XXIII. Serrasalmo>iince, American, 



uu. Premaxillary teeth in two series, teeth tricuspid or truncate ; gill-rakers various . 



XXIV. Mylince, American. 

 lih. The minute maxillary ankylosed with the premaxillary. 



V. Premaxillaries coossified ; dentaries coossified ; teeth conical or compressed, uni-, bi-, 

 or tricuspid; lateral line along middle of body; alimentary canal short ; nares close 

 together; scales ctenoid. 

 zv. Fontanel minute or absent ; maxillary bordering the mouth. 



XXV. Pliagina, African. 

 WW. A large fontanel separating the parietals and frontals to the eyes ; maxillary 

 not bordering the mouth ; snout prolonged. XXVI. Ichthyoborina, African. 

 i>v. Premaxillaries not coossified ; maxillary in part bordering mouth, its posterior, 

 toothless portion meeting the toothed part at an angle, snout not much prolonged ; 

 a few large triangular teeth in each jaw, nares close together ; lateral line below 

 the middle of body ; fontanel separating the parietals and sometimes in part the 

 frontals. XXVII. Hydrocyonimc, African. 



hhh. Premaxillaries not coossified ; maxillary not rudimentary, not ankylosed with the pre- 

 maxillary ; the teeth conical or compressed (see Bramocharax) ; nares close together ; 

 gill-membranes free from isthmus ; alimentary canal short. 

 X. Fontanel present. 



