"The labyrinths or lateral masses consists of a number of thin-walled cellular cavities, the ethmoidal air cells, arranged in two groups: anterior and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial part of the corresponding nasal cavity. In the disarticulated bone, many of these cells are opened into, but when the bones are articulated, they are closed in at every part, except where they open into the nasal cavity. The superior and middle nasal conchae are bony projections of the inner ethmoid labyrinth. Several surfaces are descibed:"
"The labyrinths or lateral masses consists of a number of thin-walled cellular cavities, the ethmoidal air cells, arranged in two groups: anterior and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial part of the corresponding nasal cavity. In the disarticulated bone, many of these cells are opened into, but when the bones are articulated, they are closed in at every part, except where they open into the nasal cavity. The superior and middle nasal conchae are bony projections of the inner ethmoid labyrinth. Several surfaces are descibed:"
"The horizontal plate features include:"
"The vertical plate forms the part of the bony nasal septum:"
"The labyrinths or lateral masses consists of a number of thin-walled cellular cavities, the ethmoidal air cells, arranged in two groups: anterior and posterior, and interposed between two vertical plates of bone; the lateral plate forms part of the orbit, the medial part of the corresponding nasal cavity. In the disarticulated bone, many of these cells are opened into, but when the bones are articulated, they are closed in at every part, except where they open into the nasal cavity. The superior and middle nasal conchae are bony projections of the inner ethmoid labyrinth. Several surfaces are descibed:"