PACIFIC SLOPE OF ECUADOR, PERU AND CHILL 523 



The genus Orcstias belongs to the highlands about Lake Titicaca 

 and the desert of Death Valley, Nevada. 



The genus Pygidium pertains to the highlands of South America. 



Of the rest of the genera Ncmatogenys, Brachygalaxias, and Per- 

 cilia are peculiar to Chili ; BasiUchthys, Hatcheria, Diplomyste, 

 Aplochiton, and Percichthys are common to Chili and Patagonia; 

 Gcdaxias, Velasia, Geotria, and Caragola are common to Chili and 

 Australia or New Zealand. 



The Calle Calle basin, which includes Lake Rinihue, contains, 

 as far as known, the richest fauna of any river basin in Chili. 



So great is the similarity of the Austro-Chilian fauna of Chili 

 with that of Patagonia, that there can be no doubt of the common 

 origin of the two faunas. 



Of the three forms of the genus Cheirodon in Chili C. GalusdcB 

 found about the Bio Bio is most typical. Both the species north of 

 this area and the one south of it have diverged from the typical 

 form. Possibly this indicates that the connection of the Chilian 

 Cheirodon with its Cisandean relatives remained longest near the 

 Bio Bio basin. 



