52 
spicuous, one behind the cerebrum, the other separating the cerebellum 
and optic lobes from the medulla. 
Figure 27. Cast of brain-cavity of Edmontosaurus (paratype, Cat. No. 2289); \ 
nat. size. A, left lateral aspect; B, superior aspect; C, inferior aspect; cbl, cerebel- 
lum; cer, cerebrum; 1. car. in, lower entrance of internal carotid artery; md, medulla 
oblongata; olf, olfactory lobes; opl, optic lobe; ptb, pituitary body; u. car. in., upper 
entrance of internal carotid artery; I, olfactory nerve; II, optic nerve; III, oculo- 
motor nerve; IV, Pathetic or trochlear nerve; V, trigeminal nerv-e; VI, abducent 
nerve; VII, facial nerve; VIII, auditory nerve; IX, glossopharyngeal nerve; X, vagus 
or pneumogastric nerve; XI, spinal or accessory nerve; XII, hypoglossal nerve. 
As seen from the side the upper outline descends rapidly in the front 
face of the cerebrum to the olfactory lobes where it continues horizontally 
forward. With the exception of the depression caused by the constriction 
behind the cerebrum, the superior outline, sloping gently forward, continues 
