24 MEMOIRS OF THE CARNEGIE MUSEUM. 



new generic or subgeneric name will have to be given to the above named 

 species. 



Nothing is said in the original description of the teeth on the maxillary of 

 Cheirodon pulcher Steindachncr. The description reads "Kieferzahne einreihig, 

 sehr klein, schlank und zahlreich." This does not apply to the genus Cheirodon, 

 in which genus it is placed by Steindachner, but applies very well to A. paraguayen- 

 sis, a species evidently very closely related to pulcher, but which has teeth along 

 the entire maxillary and belongs to the genus Holoprion as originally defined. It is 

 more than probable that pulcher also belongs here, and it is so ranked. 



Range: Guiana, Amazon, and Paraguay, rare in the Uruguay basin. 



Key to the Species op Aphyocharax. 

 a. Teeth not along the entire margin of the maxillary. (Aphyocharax.) 

 b. Dorsal without black. 



c. Maxillary with many teeth; hooks in the male confined to the lobe of the anal; a humeral spot. 



d. Mouth very large, the maxillary in fully grown specimens reaching to the third suborbital, 



2.5 in the head; snout in the adult 3.5-3.8 in the head, but very little shorter than eye; 



maxillary-premaxillary border 2.1-2.33 inhead; depth 3. 5-3.75; middle caudal rays pale. 



4. dentatus Eigenmann & Kennedy. 

 dd. Mouth moderate, the maxillary not reaching the second suborbital. 



e. Maxillary with 9-20 teeth extending over more than half the length of the maxillary; 

 scales 37-40. 

 /. Premaxillary with six to eight teeth, mandible with 16-20; middle caudal rays dusky; 

 a well-developed humeral spot; A. 17-19; depth 4.25-4.5; snout over 4 in the head; 



maxillary 3.25 in head 5. alburnus (Giinther). 



ff. Premaxillary with six teeth, mandible with about tliirteen; A. 17; middle caudal 



rays pale, caudal red in life 6. erythrurus Eigenmann. 



fff. Maxillary with teeth along about one-tliird to two-fifths its length; premaxillary 

 with seven teeth, mandible with nine; A. 18; scales 36, 8 with tubes; head 4.5; 



depth 4.5; middle caudal rays black 7. pusillus Giinther. 



cc. Maxillary with two to fourteeth, mouth small; depth 3-3.75; scales 5 or 5.5-30 to 35-4.5 to 6; 

 mandible with nine to ten teeth; hooks in the male on nearly all anal rays; no humeral spot. 



8. anisitsi Eigenmann & Kennedy. 

 ccc. Maxillary with four teeth; mouth moderate, maxiOary reaching to below anterior margin of pupil; 



depth 4.25; scales 38; A. 17 9. avary Fowler. 



66. Dorsal, at least in male, with black. Mouth minute; posterior part of anal margined with black, the 

 black extending obliquely across the lobe; hooks in the male on nearly all anal rays; depth 3; A. 19 

 or 20; maxillary very short, convex, not reaching eye, with two teeth or none; premaxillary with 



five to seven teeth; six to nine on the mandible 10. rathbuni Eigenmann. 



aa. Teeth along the entire margin of the maxillary {Holu prion). 



g. Dorsal plain; a black border or band from the tip of the last anal ray to the lobe, thence obliquely 

 to the anterior rays and forward to near the ventrals; no humeral spot; origin of dorsal behind 

 the middle; a black caudal spot. 



