eigenmann: the cheirodontin^. 15 



third; premaxillary with three or four teeth directed downward and forward, maxillary with 

 three to five similar teeth; third suborbital covering entire cheek in adult; three postorbitals 

 with only a very narrow naked border; scales small, 45-53; lateral Une complete; anal long; 



interhsemals normal 3. Probolodus Eigenmann. 



dd. Teeth slender, tricuspid, or conical in both jaws. Interhismals normal.^ 



e. Tliird suborbital covering the entire cheek, two postorbitals, of wliich the upper is minute, 



the lower very large, similar to the third suborbital, and covering the entire area from 



eye to pre-opercle; lateral line incomplete. Anal with seventeen to twenty-seven rays 



in "/" and twenty-nine to nearly forty in "ff." 



f. Anal short, with a blunt lobe or none; origin of anal behind the vertical from the middle 



of dorsal; mouth variable, maxillary with from two to twenty teeth; dorsal and ventral 



profiles similar in front of the vertical from the dorsal; caudal naked. 



4. AphyocharaxGiinther. 



ff. Anal long, the anterior rays long, filiform; origin of anal about on the vertical from 



the origin of the dorsal; mouth large, maxillary with teeth along its entire margin 



directed downward and backward, largest near the middle; ventral profile much more 



arched than the dorsal 5. Prionobrama Fowler. 



ee. Third suborbital large, the fourth in one genus at least smaller than the fifth or second post- 

 orbital. Anal with more than forty rays, its origin in advance of that of the dorsal. 

 x^. Adipose dorsal small; lateral line incomplete; anal not falcate; teeth along entire 

 maxillary; origin of dorsal but little behind vertical from origin of anal, which is 



equidistant from snout and base of middle caudal rays. 



6. Paragoniates Steindachner. 



xx^. Adipose dorsal small; lateral line complete; origin of anal equidistant from snout and 



the fourth fifth of its base 7. Leptagoniates Boulenger. 



xxx^. Noadipose; lateralline short; origin of anal equidistant from the snout and the pos- 

 terior fourth of its base 8. Phanagoniates Eigenmann & Wilson. 



eee. Tliird suborbital variable; three postorbitals, of wliichthe uppermost is minute; all of them 

 sometimes feeble. Anal moderate, its origin beliind that of the dorsal. 

 g. Teeth minute, very slender, many conical, except in No. 17. 



h. Lateral line complete; caudal lobes partly scaled; no pseudotympanum; third sub- 

 orbital covering entire cheek; postorbitals large, but feeble; maxillary without 

 teeth, its upper margin thickened; sides of lower jaw raised, without teeth; origin 



of dorsal in front of the middle 9. Parecbasis Eigenmann. 



hh. Lateral line incomplete. 



i. Anal short, of fourteen rays, the liighest extending beyond the tip of the last, ita 

 base equal to length of caudal peduncle; no teeth on the sides of the lower jaw, 

 or on the maxillary; sides of the lower jaw high, as in Parecbasis; maxillary 

 large, its outer margin very convex; lateral line very short. 



10. Leptobrycon Eigenmann. 



ii. Anal long, twenty-three to thirty rays, the highest ray not extending to the base 



of the last ray. 



* Dorsal 9-11, Cheirodontinae; the CrenuchinaB, which are similar to the foregoing, have dorsal 15-18. 



^The letters x, xx and xxx are used here out of order because text-figure 2, in which the letters were 



made to agree with those in the key, was drawn before genera 6 to 8, which are quite aberrant, were 



included in this monograph. 



