380 Evolution and Distribution of Fishes 



Centropomiis, and Lates approach near to the Percidae. 

 For the fin-formula (Dorsal i spine, 7 - 8 soft rays; ventral 

 I spine, 10-12 rays; anal 3 spines, 6-9 rays) indicates 

 an intermediate condition between average simpler percoids 

 and the higher Serranidae, while Percichthys and PercUia 

 are rather more advanced. Now these are five of the ten 

 genera that are all typically freshwater. But these five, 

 in geographical distribution, are fairly typical of the ten. 

 For Morone {Roccus, in part) mississippiensis and M. 

 multiline at a are thoroughly freshwater; M. americana in- 

 habits rivers and streams, but is at home also along the 

 Atlantic coast from Nova Scotia to Carolina. M. lineata 

 is anadromous, while M. labrax and M. punctata are es- 

 sentially coastal fishes. 



Percichthys in its three species, and Percilia in its one 

 species, inhabit the river-systems of Chile and West Argen- 

 tina; Centropomus, in its seven species, inhabits river- 

 systems from Cuba, Jamaica, and Panama, southward to 

 Rio Janeiro and interior Brazil; but they also pass out free- 

 ly into coastal regions of this area. Of the two known spe- 

 cies of Lates, one, L. niloticus is common to Senegal, the 

 Niger, and the Nile, while L. calcarifer inhabits "Coasts 

 and mouths of rivers of S. E. Asia, from India and Southern 

 China to North Australia." OUgorus, Percalates, Cteno- 

 lates, and Macquaria all inhabit the rivers of Australia, 

 while the two or three species of Siniperca occur in the 

 rivers of China, Mandschuria and Japan. 



Now all of the above fairly clearly indicates that the 

 ancestral Serranids were, like their percoid progenitors, 

 N. American freshwater fishes. These, in addition to re- 

 maining in the ancestral areas, gave off three freshwater 

 groups, as the writer would interpret. One of these, work- 

 ing down the western coast lands of S. America, spread 

 into Chili-Argentina. Another line of migrants passed 

 into E. Brazil, and thence into West Central and later into 

 East Africa by the S. Atlantis bridge. Still another, pass- 

 ing northwestward into Siberia, gave rise to the species of 

 Siniperca. 



But a striking feature of the Serranids is that some 

 species which had reached the coasts in all of the above- 



