Chap. VIII.] 



THE SKELETON. 



141 



At the sides of this great foramen are two rounded eminences 

 (the occipital condyles, oc. c., Fig. 45) by which the skull articu- 

 lates with the first vertebra. In the young rabbit this occipital 

 segment of the brain-case is not a single bone, but is composed 

 of a single median basi-occipital (b. o.) below, a single median 

 supra-occipital ($. <>.} above, and two ex-ocdpitals (e. o.), one on 



m.f. 



Fia. 45. SKULL OF RABBIT (Side View). 



a.s. Ali-sphenoid. o.o. Basi-occipital. o.s. Basi-sphenoid. /. ?. a. Foramen 

 lacerum anterius. /. 1. m. Foramen lacerum medium, fr. Frontal, i. p. Inter- 

 parietal, in. 1 and 2. Incisor teeth. Ic. Lacrymal. in. p. Maxillary process 

 of pre-maxilla. mx. Maxilla, na. Nasal, ne. Neck of tympanic, u. p. Nasal 

 process of pre-maxilla. o. p. f. Orbital process of frontal, o. p. p. Orbital 

 process of pre-sphenoid. oc. Occipital, oc. c. Occipital condyle. op. f. Optic 

 foramen, or. s. Orbito-sphenoid. p. p. Par-occipital process, pa. Parietal, per. 

 Periotic. p. mx. Pre-maxilla. pt. Pterygoid. s. m. f. Stylo-mastoid foramen. 

 s. p. /. Supra-orbital process of frontal, sq. Squamosal. t. o. Tympanic bulla. 

 z. p. sq. Zygomatic process of squamosaL zy. Jugal. 



either side. These lateral elements are produced downwards 

 into two par-occipital processes (45, p.p.). Such is the occipital 

 segment, the hindermost of the three segments of the brain-case. 



not be separated, however, until the student has some knowledge of their relative 

 positions from a study of the complete skull. An adult skull should be sawn in 

 two along the mid longitudinal line. Fig. 44, A., is a very diagrammatic view of 

 the bisected brain-case. The parts cross-shaded are where the bones have been 

 cut. The dotted lines show the boundaries of the bones in the side walls. The 

 reference numbers are to the foramina. 



