FIG. 138 



144 



Figs. 138-144. — Mandibles of Arthrodirans : Cleveland Shale, Ohio. 138. 

 Mylostoma variabilis, Newb., visceral aspect. 139. Titanichthys clarki, Newb., 

 visceral aspect. X J. 140. Tiachosteus, Newb., outer aspect. X |. 141. Diplo- 

 gnathus, Newb., outer aspect. X 1. 142. Diplognathus, seen from dorsal side. 

 143. Diplogiiathiis, visceral aspect. 144. Dinichthys intermedins, outer aspect. X \. 



137 



