Dipterus costatus Eastm. 



Page i6i 



9 Left mandibular dental plate. Natural size 



State Quarry beds (Upper Devonic) ; North Liberty, Johnson co., la. 

 Original in Museum of Comparative Zoology, Cambridge, Mass. 



Rhadinichthys sp. nov. 



{See plate g) 

 Page 172 



10 Imperfect Palaeoniscid fish, probably representing a new species of 



Rhadinichthys, in the neighborhood of R . g e i k i e i Traq. Ven- 

 tral aspect of thoracic region, showing details of pectoral fins, jugu- 

 lar plates and disarranged branchiostegals. x 2 



Chemung beds ; Warren, Pa. 



Original in Museum of Comparative Zoology, Cambridge, Mass. 



1 1 Lateral aspect of trunk of same individual as shown in figure 10. Posi- 



tion of fins, squamation, and dorsal ridge scales well displayed, x 2 



Dipterus sp. 



Page 164 



12 Worn example of palatal dental plate. Natural size 



State Quarry beds (Upper Devonic) ; North Liberty, Johnson co., la. 

 Original in Museum of Comparative Zoology, Cambridge, Mass. 



Dipterus nelsoni Newb. 



Page 163 



13 Anterolateral aspect of right mandibular plate. Natural size 

 Chemung beds ; Warren, Pa. 



Original in Museum of Comparative Zoology, Cambridge, Mass. 



14 Oral aspect of same specimen as shown in figure 13 



Dipnoan dental plate 



Page 164 



15 Undescribed, somewhat worn, Dipnoan dental plate, gen. et sp. nov. 



Natural size 

 State Quarry beds (Upper Devonic) ; North Liberty, Johnson co., la. 



Dipnoan dental plate 



Page 164 



16 Worn dental plate from same horizon and locality as that shown in 



figure 15. Natural size 



203 



