LIVING GANOIDS 



159 



recent gars, and, on the other, even as evidently to the 

 sturgeons ; of all fossil kindred of these living forms, it 

 seems most nearly in the ancestral line. 



Fig. 164. — Palcsoniscus macropomtis, Agassiz. X f. (After restoration of 

 Traquair.) Upper Permian. 



Ganoids certainly outrank the Crossopterygians in the 

 number and variety of their ancient forms. Their few 

 living representatives give but little idea of the importance 

 of the group, and can suggest but faintly the lines of its 

 evolution. 



Living Types 



The recent Ganoids include the Gar-pike, the Sturgeons, 

 and Amia. The first is of especial interest in connecting 

 the group most closely with the Crossopterygians, the last 

 as best illustrating the intermediate stage between the 

 Ganoids and Teleosts. 



The Gar-pike, Lepidosteiis (Fig. 157), resembles Polyp- 

 terus in many characters of skeleton and dermal defences. 

 It is a form not uncommon in the fresh waters of North 

 America, and is especially abundant in the Mississippi, 

 Great Lakes, and rivers of the Southern States. In South 

 Carolina the writer has known the gar-pikes to occur in 

 such numbers that they would fill the shad nets, and for 

 many days render this fishery impracticable. They some- 

 times attain a length of six feet, and are said to become 



