THE RABBIT. 



255 



its position indicates that it may have belonged originally 

 to the first. 



Study the action of atlas and axis, and note that the 

 head can be nodded backward and forward on -the atlas, 

 but that, in its rotation, the atlas turns round the odon- 

 toid process of the axis. 



III. The Skull. In the skull, note again the direction 

 of the teeth and their position in the jaws. Note the 

 articulation of the lower 

 jaw or mandible with 

 the remainder of the 

 skull. Observe the two 

 rounded occipital con- 

 dyles beside the foramen 

 magnum. Observe that 

 the orbits communicate 

 through the interorbital 

 foramen. Note that the 

 bones of the top of the 



cranium meet each other SKULL OF RABBIT (gide 



by jagged sutures. 



The following bones should be readily distinguishable 

 in an adult skull. The occipital forms a complete bony 

 ring around the foramen magnum. It is formed origi- 

 nally of a number of separate occipital bones. Proceed- 

 ing forward on the dorsal surface, a small median inter- 

 parietal bone will be found fitted in between the front of 

 the occipital and the posterior angle between the two 

 parietals, which meet by a median suture directly in front. 

 The parietals form the greater part of the roof of the 

 cranial cavity. Anterior to the parietals, a pair of large 

 frontals complete the roof of the cranium in front, and 

 send out a large crescentic process above each orbit, and 

 form the dorsal third of the orbital wall. The frontals 

 meet by a median dorsal suture. Anterior to the fron- 



