32 
Figure 1. 
Figure 2. 
Figure 3. 
Explanation of Plate III. 
Frill of Centrosaurus apertus Lambe; one-sixteenth natural size; 
superior aspect. 
Frill of Styracosaurus albertensis Lambe; one-twelfth natural 
size; superior aspect. 
Frill of Brackyceratops montanensis Gilmore; otte-eighth natural 
size; superior aspect. After Gilmore. 
