84 THE CAT. 



the foramen magnum to the front end of the middle part of the 



Fig. 48. OUTLINE OF VERTICAL SECTION OF SKULL, TO SHOW BY STRAIGHT BLACK LINES THE 

 INCLINATION OF THE BASI-FACIAL AXIS TO THE BASI-CRANIAL AXIS, AND THE ANGLES 

 FORMED WITH THE LATTER BY THE PLANES OF THE CRIBRIFORM PLATE AND OCCIPITAL 

 FORAMEN ; ALSO THE RELATIVE CEREBRAL LENGTH. 



"be. Basi-cranial axis. 



bf. Basi-faeial axis. 



c. Length from the front end. of the basi-cranial 



axis to the summit of the attachment of the 



tentorium. 



cp. Plane of cribriform plate. 



fin. Plane of foramen magnum. 



upper (or cerehral) surface of the pre-sphenoid is called the basi- 

 cranial axis (Fig. 48, be). A line drawn from the same point of the 



Fig. 49. VERTICAL ANTERO-POSTERIOR SECTION OF SKULL, MADE A LITTLE NEARER THE 

 SPECTATOR THAN THE EXACT MIDDLE LINE TO SHOW THE MEDIAN ETHMOID, ETC. 



of. Aqueduct of Fallopius. 



ai. Internal auditory meatus. 



6. Auditory bulla. 



60. Basi-occipital. 



c. Occipital condyle. 



et. Lateral ethmoid. 



/. Frontal. 



/TO. Foramen magnum. 



ip. Inter-parietal. 



me. Mesethmoid. 



ml. Ethmo-turbinal. 



n. Nasal." 

 ps. Pre-sphenoid. 

 $t. Pterygoid. 

 s. Squamosal. 

 sq. Basi-sphenoid. 

 so. Supra-occipital. 

 t. Inner surface of frontal. 

 v. Vomer. 



The anterior condyloid foramen above c 

 and bo, just over the letter 6. 



pre-sphenoid to the front part of the alveolar margin of the pre- 



