30 THE AMERICAN CHARACIDAE. 



In a recent paper (Cambridge natural history. Fishes, 1904) Boulenger 

 while recognizing that "The classification of the family is still in an unsatis- 

 factory state "divides them into the following groups (hardly deserving the rank 

 of subfamilies) " : — 



A. Erythrininae American. 



B. Hydrocyoninae African and American. 



C. Serrasalmoninae American 



D. Ichthyoborinae African. 



E. Xiphostominae American. 



F. Anostominae American. 



G. Hcmiodontinae American. 



H. Distichodontinae African. 



I. Citharininae African and American. 



Regan (Ann. mag. nat. hist., 1911, ser. 8, 8) comes to quite different con- 

 clusions in regard to the "groups" of Boulenger. He divides his Characiformes, 

 i. e. the Heterognathi of authors, into six families (a) the Characidae which 

 equals the Erythrininae, Hydrocyoninae, and Serrasalmoninae of Boulenger, 

 (b) the Xiphostomatidae = Xiphostominae of Boulenger, (c) the Anostomidae 

 = Anostominae of Boulenger plus Curimatus and Prochilodus, (d) the Hemiodon- 

 tidae = Hemiodontinae of Boulenger, (e) the Citharinidae = Ichthyoborinae, 

 Distichodontinae, and Citharininae exclusive of Curimatus and Prochilodus 

 of Boulenger, and (f) the Gastropelecidae proposed for the flying Chara- 

 cins included in the Hydrocyoninae by Boulenger. 



Regan's paper offers some criticism of my classification published in the 

 Reports of the Princeton University Expeditions to Patagonia, 1909, 3, p. 253- 

 256. In part I heartily agree with Regan, and long ago came to some of the 

 conclusions reached by him. There are, however, many points in Regan's 

 paper in which I think his conclusions are at variance with the facts. I reserve 

 my criticism of Regan's strictures and a discussion of the general classification 

 of the Characins until my study of all the subfamilies is completed. The keys 

 of the subfamilies given in the Patagonian reports do not agree entirely with my 

 present views, (cf. Rept. Princeton univ. exped. to Patagonia, 1909, 3, p. 

 253-256). 



Geographical Distribution. 



In the study of the Characins, as in that of all Tropical American fishes, 

 the question of the distribution of the genera and species must in the future be 

 among the first topics to be considered. 



In 1891 and 1892 Eigenmann and Eigenmann enumerated all the known 



