DEVONIAN FISHES OF IOWA 277 



CHIMAEROIDS. 



23. Ptyctodus punctatus Eastman. Onondaga limestone; 

 Le Eoy, New York. 



24. Ptyctodus calceolus Newberry and Wortben. Cedar 

 Valley limestone ; Iowa and Illinois. Hamilton limestone ; Wis- 

 consin and Ontario. "Cuboides zone" of tlie Devonian; Mani- 

 toba. Also Genesee and Portage groups of New York, and 

 Tipper Devonian of Iowa, Kentucky and Missouri. 



25. Ptyctodus ferox Eastman. Hamilton limestone; Mil- 

 waukee, "Wisconsin. Cedar Valley limestone and State Quarry 

 beds of Iowa. 



26. Rhynchodus excavatus Newberry. Hamilton limestone; 

 Milwaukee. Wisconsin, and Cedar Valley limestone of Iowa. 



27. Rhynchodus sp. ind. 4i Cuboides zone" of tbe Devonian; 

 Manitoba. 



28. Rhynchodus secans Newberry. Columbus and Delaware 

 limestones ; Obio. 



29. Palccomylus crassus (Newberry). Columbus and Dela- 

 ware limestones; Obio. 



30. Palccomylus frangens (Newberry). Columbus and Dela- 

 ware limestones ; Obio. 



31. Palccomylus greenei (Newberry). Hamilton limestone; 

 Milwaukee, "Wisconsin. 



32. PMyctaenacanthus telleri Eastman. Hamilton lime- 

 stone; Milwaukee, Wisconsin. 



33. Acantholepis fragilis Newberry. Onondaga limestone; 

 New York. Columbus and Delaware limestones ; Obio. 



34. Acanthaspis a rmata Newberry. Onondaga limestone : Le 

 Eoy, New York. Columbus and Delaware limestones; Obio. 

 Closely similar structures, probably dermal ossifications of 

 Bbyncbodus. occur also rn tbe Cedar Valley limestone of Iowa. 



35. Heteracanthus politics Newberry. Hamilton limestone; 

 Milwaukee, Wisconsin, and Cedar Valley limestone of Iowa. 



36. Heteracanthus uddeni Lindabl. Hamilton limestone; 

 Milwaukee. Wisconsin, and Cedar Valley limestone of Iowa. 



37. Machaeracanthus peracutus Newberry. Columbus and 

 Delaware limestones; Obio. Onondaga limestone; Le Eoy and 

 Lime Eock. New York. 



