88 
Plate XII 
Right ramus of H ypacrosaurus altispinus Brown. No. 8501, Geol. Surv., Can. Viewed, from 
the internal side. An, angular; Ar, articular; Cp, coronoid process; Dn, dentary; Par, prearticular 
S, symphysial border. About one-third natural size. (Page 50.) 
