1903.] Gregory, The Shortening of the Elephant's Skull. 393 



ward, outward, and downward; especially internall}^ the 

 fore-and-aft extent of the alisphenoid proper is brief. 



Internally the skull has shortened up, one might almost say 

 in bellows fashion, with the optic foramen on each side at the 

 apex of the internal transverse folding (PI. xxiii), the ridge 

 of the "lesser wing " of the human sphenoid. As the skull 

 has also expanded transversely, the general effect of the in- 

 ternal view of the skull is thus that of compression around the 



Fig. 4. Orbito-sphenoidal region, left side. From Osborn. The view is obliquely from the 

 side and from below the malar bone (compare Fig 3). 



Po.f. — Post-orbital ridge of frontal. 

 Fr. — Frontal. 



O. s. — External process of orbitosphenoid. 

 As. — Alisphenoid. 



FORAMINA, ETC 



BONES. 



Sg'. — Squamosal. 



/. As. — Pterygoid wing of alisphenoid. 



yi/^. ;>. — Maxillary pouch for molars. 



o/.y. — Foramen opticum. 



y. I. a. — Foramen lacerum anterius. 



y. r. and a. a. s. — Arcade leading to foramen 

 rotundum and anterior opening of the ali- 

 sphenoid canal. 



center (represented by the basisphenoid) and increasing ex- 

 pansion toward the periphery — somewhat recalling the con- 

 ditions of the domelike human skull. Between the frontal and 

 temporo-sphenoidal fossae, which form a large trefoil as seen 

 from above, there is on each side, running obliquely outward, 

 forward, and upward, a prominent triangular buttress, the 

 transverse ridge mentioned above, to the formation of which 

 the orbitosphenoid, frontal, and parietal contribute. On each 



