VI. THE SCALES OF THE SOUTH AMERICAN 

 CHARACINID FISHES. 



By T. D. a. Cockerell. 



(Plates XXIII-XXVIII.) 



In the Smithsonian Miscellaneous Collections, Vol. 56, No. i (1910) 

 I reported on the scales of the African Characinidae. It has been a 

 great pleasure, for which I am indebted to Dr. Eigenmann, the Curator 

 of Ichthyology in the Carnegie Museum, to now examine the scales 

 of the South American species, or at least a considerable number of 

 them. The investigation emphasizes the well-known fact that the 

 American Characinids are not only much more numerous, but also 

 very much more diverse than those of Africa. It further indicates, 

 that 



1. The strongly ctenoid Dist'chodontine type of scale is represented 

 only by Ctenohrycon in America. The nearest other approach known 

 to me is found in Luciocharax, which seems to be a sort of connecting 

 link with the Alestines. I know the Luciocharax scale only from a 

 figure. 



2. The Hemigrammus type of scale, so abundantly represented in 

 America, is totally wanting in Africa. 



3. The African and American series come together in the Alestines, 

 particularly in such types as Chalceus macrolepidotus and Alestes 

 macrolepidotiis. 



4. The Erythrinines, so far as squamation goes, connect up with the 

 Old World Cyprinids. 



5. If Iliodon (which has completely transverse apical circuli) has 

 any relationship with the Characinids, it must be with the Curimatines, 

 although the Serrasalmonine scale is not without resemblances, the 

 system of circuli being about the same. Iliodon tergidus has the fine 

 pustular markings seen in Curimatiis spiliirus. I figure (Plate XXV', 

 fig. 3) Iliodon tergidus from Wisconsin (Polk County, Graenicher). 



6. I cannot at present connect the Catostomids with the Characinids 

 through the scales. Moxostoma aiireoliim has a very Erythrinine- 

 looking scale, hut the apical circuli are entirely transverse. 



With regard to the history of the Characinids, the obvious indica- 



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