PLATE 57 

 Figs. I, 2. Chetrolepis canadetisisWhitesiyes. Enlargement of scales, X about 



25- 



Both figures from E 2558, p. 181. 



Fig. 3. Scaumenacia curta (Whiteaves). Impression of posterior portion of 

 upper surface of head, showing sutures and sensory canals. Near the head is seen 

 the dentition. E 2521, p. 172. 



Fig. 4. Scaumenacia curta (\ATiiteaves) . Dentition shown in preceding figure, X 3. 



Figs. 5, 6, 7, Enlargement of shagreen scales found isolated in the Conodont 

 bed. Fig. 6 is the under side of a scale like that in Fig. 5, and shows a flange for 

 overlap. 



312 



