CHAKACINIDiE. 607 



Cyprinoids proves only that that continent is nearer to the 

 original centre, from which the distribution of Cyprinoids 

 commenced than tropical America. The family includes 

 herbivorous as well as strictly carnivorous forms ; some are 

 toothless, whilst others possess a most formidable dentition. 

 The family contains so many diversified forms as to render 

 a subdivision into groups necessary. They have not yet 

 been obtained in fossiKferous strata. 



I. Erythkinina. — Adipose Jin absent. 



The sixteen species of this group belong to the fauna of 

 tropical America, and are referred to the genera Macrodon, 

 Erythrinus, Lebiasina, Nannostomus, Pyrrhulina, and Cory- 

 nopoma. 



IT. CUEIMATINA. — A short do7'sal and an adipose Jin; 

 dentition iinperject. Tropical America. 



CURIMATTJS. — Dorsal fin placed nearly in the middle of the 

 body ; anal rather short or of moderate length ; ventrals below 

 the dorsal. Body oblong or elevated, with the belly rounded or 

 flattened before the ventrals. Cleft of the mouth transverse, 

 lips none, margins of the jaws trenchant. No teeth whatever. 

 Intestinal tract very long and narrow. 



About twenty species are known, of rather small size. 



The other genera of this group have teeth, but they are 

 either rudimentary or absent in some part of the jaws : Pro- 

 cJiilodus, Ccenotropus, Hemiodus, Sdccodon, Parodon. 



III. CITHAEININA. — A rather long dorsal and an adipose 

 Jin ; minute labial teeth. Tropical AJrica. 



One genus only, Citharinus, with two species, is known. 

 Common in the Nile, attaining to a length of three feet. 



IV. Anastomatina. — A short dorsal and an adipose Jin; 

 teeth in loth jaws well developed ; the gill-membranes groiun to 



