62 ANNALS NEW YORK ACADEMY OF SCIENCES 



/ balzanii, 

 Geophagus brasiliensis .| brachyurus, 

 I gymnogeyns, 

 gymnogeyns, 

 brachyurus, 

 balzanii, 

 JEquidens portalegrcnsis = Cichlasoma bimaculatiim, having only one 



anal spine more, 

 Cichlasoma facetum, 



Crenicichla lepidota, southern form of C. saxatilis, 

 lacustris, 

 vittata, southern form of C. macrophthalmus. 



These species are found on both sides of the divide in the State of Eio 

 Grande do Sul. The region is characterized by Geophagus gymnogeyns 

 and brachyurus. 



Alto Parana and Coastwise Streams of Eastern Brazil 



This complex is characterized by higher altitudes, numerous water- 

 falls, rapid water, sub-tropical temperature and forests. It harbors the 

 following species of the Cichlidse : 



Geophagus brasiliensis with two varieties, 



„ . . , 7 7 . . f C. jaguarensis, 

 Crenicichla lacustris 1 _, . 



| C. iguassuensis, 



vittata (C. dorsocellata, southern form of C. macrophthalmus) , 



lepidota, southern form of C. saxatilis, 

 Cichlasoma facetum (C. autochthon and C. oblongum being synonymous), 

 Cichlasoma bimaculatiim, northern form of sEquidens portalegrcnsis. 



These six species and their varieties are found on both sides of the 

 divides between the headwaters of the Alto Parana and the coastwise 

 rivers of eastern Brazil. This region is characterized by two varieties of 

 Geophagus brasiliensis, two varieties of Crenicichla lacustris and one 

 variety of Crenicichla vittata. Whether these varieties will breed true or 

 whether they exhibit only somatic changes which are not necessarily 

 inherited is not known, but they show, at any rate, changes due to the 

 peculiar environments in which they live. For example, the young of 

 Geophagus brasiliensis var. iporangensis could not be distinguished from 

 the young of the common form, but the adults were strikingly different. 

 The variety lived in the rushing headwaters of Eio Eibeira and the com- 

 mon form, G. brasiliensis, lives more in the lowland sections of the rivers, 

 lagoons and swamps. I observed a similar change from lowland to high- 

 land forms near Santos. I also observed that Geophagus brasiliensis 



