202 21u' South American Characinidse 



23. li('|M»i-iiiiis coil ii'osf lis. 



StciiKliU'lmcr Sitzb. K. K. Akad. Wiss. Wien. LXXI., 23, pi. IV.; 

 Eiyc'inn. & Eijj;eiim., Proc. U. S. Nat. Mus., XIV., 51, 18J)1. 

 \V\o Parabyba, one specimen. 



TkTRAGOXOI'TEKIN.E. 



Teti-au:oii<»|>tei-iis Cuvier. 



Teiragonopterus Cuv., Regne Anim., II., 166, 1811(argenteus); id, Meiu. 

 Mus., IV., 455, 1818. 



letmgonoptcrvs Swainson, Nat. Hist., II., 289, 1839 (aureus and chal- 

 cetis). 



Teiragonopterus Liitken, Velhas-FIodens Fiske, 206, 1875. 



Tetragonoptenis Eigenni. it Eigenm , Proc. U. S. Nat. Mus.. XIV., 52, 

 1891. 



Po'cilii.ric7ithi/s 0\\\, Ann. N. Y. Lyceum Nat. Ilist., 54, \So8 (brevoorti) . 



Jle/nmigrdnnnns (iill. 1. e. (unilineatns). 



Anfi/diia.v Cwiivd, U. S. ]Mox. Hound. Survey, 74, 1859 (nrgentaius). 



Creatochanes Giinther, Cat. Fish. Brit. :Mus. V., 318 and 329, 1864 

 {melanunis). 



Ilemibri/con Giinther, Cat. Fish. Brit. Mns., V., 318 and 330, 1864 

 (poli/odon) . 



Typo : Tetragonopterus argenteus Cuvier. 



Various species of the genus Tetragonopterus have been taken 

 for types of distinct genera. However desirable it would be to 

 divide this large genus into smaller ones, the characters hereto- 

 fore used to designate the new genera are so variable in dirterent 

 species that they cannot even be considered of subgeneric value. 

 The completeness or incompleteness of the lateral line, which was 

 taken as one of these characters, is found to varv in some of the 

 species. The completeness or incompleteness of the dentition of 

 the maxillary seems not more fortunate as a character for generic 

 division. I am not familiar with T. meJanurus or any of the 

 other members of this supposed subgenus, and cannot say Mhether 

 its i'h:iraeters are valid. For the present nil of these forms have 

 beeji united under the generic name Tetragonopterus. 



The species may be distinguished by the following synopsis : — 



1. Lateralline complete, 

 a. Anal rays 40 or more.* 



b. Scales in the lateral liue 30. 



• T. caucanus hasaniil ravs 3S?— U. 



