ON THE SPECIES OF THE GENUS CHALC1NUS. 6 



Scales from upper edge of gill-opening to caudal 40-47 ; 

 rays in the anal fin 27-32 ; 



first anal ray behind the dorsal . O. elongatus. 

 rays in the anal 30-34 ; 



first anal ray beneath middle of dorsal G. culler. 

 rays in the anal 35-41 ; 



first anal ray in front of dorsal G. magdalence 



CHALCINUS ANGULATUS Spix and Ag. ; C. V. 

 G. brachipomus C. V. 

 G. mulleri Fil. 

 (7. trifurcatus Cast. 

 (7. nematurus Kn. 

 Triportheus flavus Cope. 



Valenciennes states in his description of (7. brachipomus 

 that the length is about three and a half times the height 

 and nearly five times the length of the head, which propor- 

 tions, together with the characters assigned it, seem to ne- 

 cessitate placing it as a syuonyme with (7. angulatus. G. 

 brachypomus of Gunther is so different in essential respects 

 from that of Valenciennes that the two cannot be considered 

 identical. On typical specimens of (7. angulatus the labial 

 folds and the barbels are short, apparently ; in this and in 

 the other species, they are longer in the young than in the 

 old, and it may be they are the more developed in the 

 spawning season. One of the varieties has a length of barbel 

 that equals or exceeds the diameter of the eye. Examina- 

 tion of a large number of specimens discloses no variation in 

 the number of scales (6) between the first ray of the dorsal 

 and the lateral line. Hab. Coary, Cudajas, Fonteboa, 

 Hyavary, Ia, Jutahy, Lake Hyanuary, Lake Jose Assu, 

 Manacapouru, Manaos, Obydos, Santarem, Silva, Lake Sa- 

 raca, Tabatinga, Tefie, Tonantins. 



The species as represented in the collection is separable 

 into four varieties beside the type form. 



