FIG. 138 



144 



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

 Mylostoma variabllis, Xewb., visceral aspect. 139. Titanichthys clarki, Newb., 

 visceral aspect, x g. 140. Trachosteus, Newb., outer aspect. X 5. 141. Diplo- 

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

 143. Diplognathns, visceral aspect. 144. Dinichthys intermedius, outer aspect. X 5. 



137 



