The Coming of Vertebrates and Rise of Fislies 



just described. This animal, known as Palce- 

 ospondylus gunni, while only from an inch to 

 an inch and a half in length, had a better-de- 

 fined skeleton than the lampreys of to-day, and 

 so is rather highly specialized. 

 But it must have descended from 

 much simpler species, and some 

 of these may have varied in other 

 directions, and have been the an- 

 cestors of the strange little ar- 

 mored "fishes." 



The coast of ancient North 

 America seems to have been 

 poorer in fishes than were the 

 waters about early Europe, for 

 many more of these quaint ar- 

 mored creatures have been dis- 

 covered in Eno-land and on the 

 Continent than here. It may be 

 that we have not yet discovered the burial- 

 places of the little fellows, and that some day 

 they will be brought to light, but at present 

 we miss many of the forms found on the 

 other side of the water. 



97 



PalcBospondylus 

 gunni, a very 

 ancient ances- 

 tor of the lam- 

 preys. (After 

 Traquair.) 



