THE SKELETON. 3! 
auditory meatus, which gives passage to the auditory nerve. 
Close examination reveals a division of the canal into two 
parts, a ventral for the eighth nerve and a dorsal, the aque- 
ductus Fallopu, for the facial nerve. This aqueduct twists 
through the petrous laterad, and thence between the petrous, 
squamosal, and mastoid to the stylomastoid foramen (Fig. 
Taye) 
The parietal bone is paired and joins its fellow in the 
median line, forming the caudal half of the sagittal suture. 
Its point of greatest convexity is the parietal eminence. Its 
cerebral or internal surface presents slight arborescent 
grooves which in the recent state sheltered the meningeal 
artery of the brain. The plate of bone projecting obliquely 
craniad from the caudal border of the parietal is the tento- 
rium, an ossification of the dura mater separating the cere- 
brum from the cerebellum. 
The interparietal is a triangular bone situated at the 
junction of the two parietals and occipital bones. Its 
sutures are usually obliterated quite early. 
_The occipital (Figs. 16, 17, and 18) is a single bone 
surrounding the foramen magnum and articulating with 
the interparietal, parietals, temporals, and sphenoid. In the 
young kitten it is composed of four parts: the supraocci- 
pital, lying dorsal to the foramen magnum, the two exocct- 
pitals, lying laterad of it, and a basioccipital, bounding it 
ventrally. The crescentic elevation on the supraoccipital 
near its parietal margin is the lambdoidal ridge, to which 
several muscles are attached. 
The exoccipitals bound the cerebellum laterally and sup- 
port the occipital condyles, which articulate with the atlas 
or first vertebra. Immediately caudad of the bulla is the 
paroccipital process. There are two foramina, one of 
which, the anterior condyloid, opens ventrally with the jug- 
ular foramen adjacent to the bulla, while the other, the 
