2 ON THE SPECIES OF THE GENUS CHALCINUS. 



the short variety of G. angulalus that absence of the feat- 

 ures mentioned would be rather unexpected, and if pres- 

 ent, as I have no doubt they are, they should be placed 

 among the generic characters. There are two series of 

 intermaxillary teeth in young specimens. On the other 

 hand, old specimens apparently have three more or less 

 perfect series in the same region. This difference in in- 

 dividuals of the same species is brought about somewhat 

 as follows : the third tooth of the inner row on each side of 

 the symphysis is crowded outward to take a position be- 

 tween the two rows ; then, as the growth of the specimen 

 continues, the first tooth on each side of the middle of the 

 outer row is crowded inward, the third tooth of each sec- 

 tion of this series afterward follows in the same direction, 

 and slill later the fifth tooth shows a disposition toward sim- 

 ilar displacement, thus eventually producing what might be 

 described as a triserial arrangement of the intermaxillary 

 teeth. The amount of curvature from snout to tail, in the 

 dorsal outline, as given in descriptions is to be taken with 

 some allowance ; it varies greatly with the age and degree 

 of plumpness of the individual and also changes in death 

 and in alcohol. Including several varieties, the following 

 species seem to be all that can be recognized at present. 

 Scales from upper edge of gill opening to caudal 30-40 ; 

 rays in the anal fin 24 (23) ... (7. pictus. 

 rays in the anal fin 28-33 ; 



from dorsal to lateral line 6 scales ; 



lateral line of 32 scales . C.paranensis. 

 lateral line of 33-40 scales C. angulatus. 

 from dorsal to lateral line 5 scales ; 



base of anal extending beneath that of dorsal ; 

 form short and deep . G. guntheri. 

 base of anal behind that of dorsal ; 



form elongate .... (7. albus. 



