366 



PATAGONIAN EXPEDITIONS : ZOOLOGY. 



of marine families that require no change in the present conditions to 

 account for their origin. 



The second group comprises the LepidosirenidcE, Osteoglossidcs, Siliir- 

 idce, Characidce, Poeciliidcs and Cich/idcs. 



Of these, the Lepidosiyenidce are rehcts of a formerly widely distributed 

 group, and it requires no land connection satisfactorily to account for 



Range of the Lepidosirenidae. 



Range of the Osteoglossidas. 

 To Illustrate the Origin of the South American Fresh-water Fish-fauna. 



