58 
Plate X. 
Figure 1. Ceraurus dentaius Raymond and Barton. (Page 35.) 
A nearly complete specimen from the upper Trenton 
(■Cobourg) at Cobourg, Ont. Natural size. No. 1769b. 
Figure 2. The same species. An incomplete specimen on which the 
ornamentation is especially well shown. From the Hull 
formation at Belleville, Ont. Natural size. No. 1769. 
Figure 3. The same species. The largest specimen so far found. From 
the Hull formation at Belleville, Ont. Natural size. No. 8062. 
