128 Annals of the Carnegie Museum. 



c. Maxillary with usually conical teeth along its entire edge. 



Holopristis Eigenmann. 

 cc. Maxillary with 0-5 conical or multicuspid teeth at its anterior upper 



end Hemigrammus Gill. 



bb. Lateral line complete. 



c. Maxillary with 0-10 teeth. 



d. Nape rather abruptly elevated, profile very concave, depth less than 

 half the length, preventral region flat, with lateral keels. 



Tetragonopterus Cuvier. 



dd. Profile little if at all concave, depth usually less than half the 



length, preventral region rounded. Astyanax Baird and Girard. 



cc. Maxillary with teeth along its entire edge Hemibrycon Giinther. 



aa. Caudal scaled. 



e. Anal scaled, long, rounded, with over 40 rays Markiana Eigenmann. 



ee. Anal naked, with 23-28 rays. 



f. Premaxillary teeth parallel .• Moenkhausia Eigenmann. 



ff. Anterior series of premaxillary teeth in a wavy line. 



Bryconamericus Eigenmann. 



Key to the Species of Astyanax Baird and Girard. 

 a. Anal rays 30 to 49. 



b. Lateral line 55 ; anal 45 ; head 3.6 ; depth 2.63 ; lateral line 55. Eye 

 greater than snout by one third of its diameter, greater than interorbital^by 



\-\ of its diameter erythropterus (Holmberg) 1. 



bb. Lateral line with 50 scales or fewer. 

 c. Anal 40-48. 



d. Scales 42-50. 



e. Anal 47-48 ; scales small, 47 in lateral line. 



f. A few rudimentary teeth on the maxillary ; a silvery lateral 



band ; ventral profile much arched ; snout pointed ; 



A. 48 spilurus (Cuvier & Valenciennes) 2. 



ff. No teeth on the maxillary ; a very distinct silvery lateral 

 band ; an indistinct caudal and humeral spot ; maxillary 

 reaching anterior margin of orbit ; depth 2.3 ; eye 3 in. 

 the head ; scales 9 or 10-47-10 or 11 ; A. 47. 



hauxwellianus (Cope) 3 

 ee. Anal 41-45. 



g. Scales 8-46-8 ; two teeth on maxillary ; lateral band not 



conspicuous ; humeral spot bordered with silvery in front 

 and behind ; caudal spot large, continued to end of 

 middle caudal rays ; depth 3 ; eye 2^ ; A. 41. 



riveti Pelegrin 4. 



gg. Scales 10-45 to 5°~8 or 9 ; a small silvery lateral band ; 



a dark spot on shoulder and one on base of caudal 9 



9 These spots are very obscure in alcoholic specimens, while in specimens first pre- 

 served in formalin they are conspicuous and a black band replaces the silvery band of 

 the alcoholic specimens. 



