=The Quadrate.= _Location._—The quadrate bones, or ossa quadrata, two in number, are located antero-laterally to the temporal bones. Each articulates inferiorly with the posterior articular portion, or pars articulare, of the inferior maxilla and infero-laterally with the quadrato-jugalare portion of the zygomatic. It articulates antero-internally with the pterygoid and supero-posteriorly with the temporal. _Description._—The quadrate bone is anvil-like in shape. It has an anterior process, the orbital process, for muscular attachments, and posteriorly it affords attachment to the ear drum. =The Inferior Maxilla.= _Location._—The inferior maxilla, lower jaw, or os maxillare inferius, also called the mandibular bone, or pars dentis, is analogous to the lower jaw of mammals. It articulates posteriorly with the quadrate bone. _Description._—The inferior maxilla is the largest bone of the face. It is made up of a _right_ and a _left limb_ which are separate in the fetus and which unite subsequently anteriorly, forming the inferior portion of the beak. Each limb of the jaw is developed from five elements: the _pars articularis_, which forms the jaw-joint and, expanded, articulates with the quadrate bone; the _pars angularis_, lying just in front of the pars articularis; the _pars supra-angularis_, a slender bone lying just above the angularis; the _splenial_, a thin plate of bone, lying along the inner surface of the mandible; and the _pars dentalis_, which forms the anterior portion of the jaw. =The Turbinate Bones.= _Location._—The turbinate bones, or ossa turbinata, six in number, are attached to the lateral walls of the nasal cavity (Fig. 26, No. A, 1 and 2). In each nasal cavity there are three turbinate bones, one anterior and two posterior. Of the two posterior the upper one lies supero-posterior to the inferior one. The turbinate bones are attached to the lateral nasal walls, project into the cavity and thus greatly diminishing its extent. _Description._—Each turbinate bone is composed of a very thin lamina, finely cribriform in many places, and in the fresh state, covered on both sides with mucous membrane. These bones are curled and partly membrano-cartilaginous structures which give greater surface in the nasal passage for mucous membrane in which the olfactory nerve terminal filaments are distributed. =The Nasal Cavity.=—The nasal cavity, or cavum nasi, is a longitudinal passage which extends through the upper part of the face. It is divided into right and left halves by a median septum nasi. Its walls are made up of the premaxilla, maxilla, nasal, vomer, and palatine bones. =The Hyoid Bone.= _Location._—The hyoid bone, or os hyoideum, is situated chiefly between the rami of the mandible, but its upper part extends around the outer margin of the base of the skull. The hyoid bone does not articulate with any bones of the skull, but is firmly attached by strong fibrous structure.