Class Osteichthyes

Abstract

The ray-finned ‘bony fishes’ include all the commonest marine species of to-day (e.g. cod, sole, herring, eels) as well as the numerous forms that occur in freshwater lakes and streams of almost every country. They include also some of those peculiar and archaic survivals which used to be called ‘ ganoids ‘ (pp. 287, 326)—e.g. the sturgeons, Garpike (Lepisosteus)¹ and the Bowfin (Amia) (p. 292). Other survivors of ancient lines, Polypterus and Erpetoichthys (p. 290), which were once placed with the crossopterygians—lung-fishes (p. 361) and cœlacanths (p. 356)—are now believed to be actinopterygians.