The skull or bony framework of the head is situated at the anterior extremity of the vertebral column, from which it is suspended by ligaments and muscles, and on which it is capable of being freely moved in all directions. It forms a number of cavities for the lodgment of important organs, as the cranium, the orbit, and the mouth.

In the young animal it is made up of thirty-two pieces or separate bones, all of which, excepting the lower jaw and the hyoid or tongue bone, become united in the adult by ossification. Of the thirty-two bones, the following six are single: -

Occipital Bone. Sphenoid Bone.

Ethmoid Bone. Vomer.

Inferior Maxillary Bone or Lower Jaw. Hyoid or Tongue Bone.

The rest are in pairs: -

Parietal Bones.

Frontal Bones.

Squamous Temporal Bones.

Petrous Temporal Bones.

Nasal Bones.

Superior Maxillary Bones.

Anterior Maxillary Bones. Malar Bones. Lachrymal Bones. Palatine Bones. Pterygoid Bones. Turbinated Bones (two pairs).

The head is divided into the cranium and the face.