PLATE XLVI. 



Jurassic Dinosaurs. — Predentata. 



Stegosaurid^e. 



Page. 



Fig. 1. Brain cast of Stegosaurus ungulates Marsh ; seen from above 190 



e, cerebral hemispheres ; cl>, cerebellum ; m, medulla; ol, olfactory lobes; 

 on, optic nerve; op, optic lobes. 

 Fig. 2. Cast of neural cavity in sacrum of Stegosaurus ungulalus; side view .. 190 



Fig. 3. The same cast ; seen from above 190 



a, anterior end; /,/',/", foramina between sacral vertebra?.; p, exit of 

 neural canal in last sacral vertebra. 

 Fig. 4. Outlines representing transverse seel ions through same brain and 



sacral cavity 190 



6, brain; «, sacral cavity. 

 All four figures are one-fourth natural size. 

 Fig. 5. Sacrum and ilia of Stegosaurus ungulatus; seen from below ; one-twelfth 



natural size 190 



a, first sacral vertebra; ae, acetabular surface; b, transverse process of 

 first sacral vertebra; e, transverse process of last sacral vertebra; 

 il, ilium; I, second lumbar vertebra from sacrum; V , lumbar vertebra 

 next to sacrum ; p, last sacral vertebra. 

 336 * 



