LIST OF ILLUSTRATIONS 



LIST OF ILLUSTRATIONS 



PLATES PAGE 



Map showing progress of detailed mapping, to face 1 



I. Teeth and other fossilized portions of Devonian fishes from the 



United States and Rhenish Prussia 294 



II. Teeth and dermal plates of Devonian and Kinderhook fishes from 



the United States and Rhenish Prussia 298 



III. Spines, mandibles and surface ornamentation of fishes from the 



Devonian and Kinderhook of the United States and Germany. . 303 



IV. Dinichthys pustulosus Eastm. Lower part of the Cedar Valley lime- 



stone; near Rock Island, Illinois. Dorsal aspect of moderate- 

 sized headshield, showing cranial sutures, sensory canals and 

 other features 308 



V. Examples of Ptyctodont dentition from various Devonian localities 312 



Figs. 1-17. Ptyctodus calceolus Newb. & Worthen. State Quarry 



beds (Upper Devonian); Johnson county, Iowa. Upper and 



lower dental plates. 



Figs. 18-27. Ptyctodus compressus Eastman. State Quarry beds; 



Johnson county, Iowa. 



Figs. 28-30. Ptyctodus inolaris Eastman. Middle Devonian; 



Eifel District, Rhenish Prussia. 



Figs. 31-34. Ptyctodus panderi Eastman. Middle Devonian; 



Eifel District, Rhenish Prussia. 

 VI Examples of Ptyctodont dentition from the Iowa Upper Devonian 316 



A miscellaneous assortment of detached tritors, the greater 



number of which belong to Ptyctodus calceolus Newb. & 



Worthen. 

 VII. Examples of Ctenodipterine dentition, mostly from the Iowa Upper 



Devonian 320 



Figs. 1-4. Dipterus nelsoni Newberry. Chemung; Warren, 



Pennsylvania. 



Figs. 5-9. Dipterus mordax Eastman. State Quarry beds; John- 

 son county, Iowa. Small sized examples of the inferior dental 



plates. 



Figs. 10-15. Dipterus pectinatus, sp. nov. State Quarry beds; 



Johnson county, Iowa. Lower and upper dental plates. 



Figs. 16-25. Dipterus digitatus, sp. nov. State Quarry beds; 



Johnson county, Iowa. Lower and upper dental plates. 



