'isol'^'] PROCEEDIXGS OF THE NATIONAL MUSEUM. 13 



Dr. Giiutber^ treats of the distribiitiou of South American fishes 

 iiore in general. He divides South America into the neotropical 

 region and the Fuegian subregion, separated by a line from the tropic 

 •until it strikes the western slope of the Andes * * * where it 

 again bends southwards to embrace the system of the Rio de la Plata." 

 Leaving out of consideration all the marine forms entering or inhabit- 

 ing rivers, he enumerates 673 fresh-water fishes in the whole of the 

 neotropical region, including Mexico and the West Indies. This sub- 

 division of thti South American portion of the nootropics is a natural 

 one as far as fishes are concerned, and it is adopted here. 



Before discussing the subregions, provinces, etc., more in detail, we 

 present the following lists of genera peculiar to the different localities. 

 Since almost all genera are here accounted for, it will be seen that 

 South America is divided into well-defined provinces. 



I. 



Genera peculiar to Chili, Patagonia, Argentine Republic, and Terra 

 del Fuego : 



1. Diplomystes 1 sp., Chili 



2. Nematogeuys 1 sp., Chili 



3. Percichthys.4 sp., Chili and Patagonia 



4. Percilia 1 sp., Chili 



(Petromyzoutida?. ) 



These genera, four in number, are the only ones inhabiting the large 

 Fuegian subregion of the southern zone which are not also found in the 

 Brazilian subregion. Several genera of wide distribution, especially 

 Pygidium, have representatives here. 



The following lists, exclusive of xvii and xviii, characterize the 

 Brazilian subregion. A few of the genera have also representatives in 

 the Mexican subregion. 



II. 



Geiiera with representatives in all or nearly all the rivers from the 

 La Plata to the Magdalena. Those having representatives on the 

 western slopes are marjjed with an asterisk (*), those not yet recorded 

 from the La Plata are marked with a dagger (t), those not yet found 

 in the Rio Mag<lalena are marked with a double dagger (|): 



1. Pseudopimelodus 6 sp, 



2. Rhamdia * 22 sp. 



3. Pimelodella 12 sp. 



4. Pimelodus 13 sp. 



5. Trachy corystest 13 sp. 



6. Pseudanchenipterust 4 sp. 



7. Ageneiosus 12 sp. 



8. Loricaria 34 sp. 



9. Plecostomus* 28 sp. 



10. Rhinelepist 3 sp, 



11. Callichthysi 2 sp. 



Described as 11 species. 



12. Hoplosteruumt 3 ap. 



Described as 13 species. 



13. Corydorast 12 sp. 



14. Macrodou 2 sp. 



Described as 12 species. 



15. Erythriuust 4 sp. 



1 The Study of Fishes. Black : Edinburgh, 1880. 



