cess of jugal [3]. An area [4] along the sagittal margin [5] 

 of the upper surface for articulation with the basisphenoid, 

 is continued backwards on to the basitympanic portion of 

 the bone. The remainder of the upper surface of the 

 pharyngeal portion is divided by the base of the epipterygoid 

 process [6] into narrow jugular [7] and extensive orbital [8] 

 surfaces. The epipterygoid process is a triangular plate 

 of bone, whose base crossing the pharyngeal portion 

 obliquely from before backwards and laterally reaches the 

 anterior limit of the basitympanic portion. Behind this 

 process and placed more laterally upon the upper surface 

 of the basitympanic portion is the much smaller prootic 

 process [24]. Medial to the last is a deep and wide jugular 

 sulcus [9], The medial wall of the jugular sulcus is the 

 outer side of a raised trangular surface for articulation 

 with prootic [10] and basisphenoid [11] bones. Medially 

 this raised area overhangs the anterior aperture of the 

 carotid canal [23] whereby a short sulcus [12] is formed, 

 which is converted into a canal in the articulated skull by 

 the basiphenoid bone. Immediately to the inside of the 

 carotid sulcus is another small area [13] for articulation 

 with the basisphenoid. The remaining portion of the upper 

 surface of the basitympanic portion of the bone forms part 

 of the floor of the acustico-jugular cavity [14]. The whole 

 lateral edge of this part of the bone [15] articulates with 

 the quadrate. The posterior aperture of the carotid canal 

 [16] is flanked medially by a flattened paroccipital lamina, 

 :17] which shares in the formation of the paroccipital 

 process. The paroccipital rami of exoccipital and basi- 

 occipital which complete that process articulate with the 

 medial surface of the bone, the two articular areas [18 and 

 19; being quite distinct. Springing from the lateral aspect 

 of the epipterygoid process and extending back and ventrally 

 towards the quadrate surface of the basitympanic portion, 

 is a flange of bone (crista pediculnns) ]'20) which overhang- 



