Fig. 5 Brain case of young Erinaceus europaeus. After. Parker (1885, p. 19, 
fig. 4) Seen from above. 
The orbitosphenoid is posterior to the ethmoid, lateral to the presphenoid, anterior to the sphen- 
orbital fissure, (f.l.a.), lateral to the basisphenoid and pituitary fossa, anterior to the prootic and 
chiefly anterior to the foramen ovale (V3). 
Fig. 6 Median section of skull of the Cynodont Diademodon. From Broom 
(P.Z.8., Dec., 1911, pl. xlvi, fig. 9) 
The alisphenoid (A.S.) has the same topographic relations as the alisphenoid of mammals. It also 
appears to be homologous with the alisphenoid of Crocodiles and Dinosaurs. The opening in front of 
the prootic is believed to be the foramen prooticum (for V2, V3). The small spicule of bone that 
divides this opening is thought by Broom to have been medial to the Gasserian ganglion. 
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