Sp 
Roa Od © | ry Ee 
Figs. 138-144. — Mandibles_of Arthrodirans: Cleveland Shale, Ohio. 138. 
variabilis, Newb., visceral aspect. 139. Tifanichthys clarki, Newb., 
visceral aspect. x }. (140,) Trachosteus, Ne@Mib., outer aspect. X }. 141. Diplo- 
, Newb., outer aspect. xX }. 142. Diplognathus, seen from dorsal side. 
(AS Ritlagnathes, visceral aspect, 144. Dinichthys intermedius, outer aspect. X 4. 
137 
