In humans and most mammals the base of this structure is formed by the signet-shaped cricoid cartilage, which lies posterior to the thyroid cartilage, its most ventral portion.  
The cuneiform and corniculate portions of it are immediately dorsal to its most ventral section.  The paired and pivoting arytenoids act as a moveable posterior attachment for it and the muscles that regulate it.  In humans and most mammals the base of this structure is formed by the signet-shaped cricoid cartilage, which lies posterior to the thyroid cartilage, its most ventral portion.  Above it lies the structure that sometimes serves as its lid, the epiglottis.  FTP, name this chamber which leads from the lower pharynx to the trachea and is commonly called the voice box.
The cuneiform and corniculate portions of it are immediately dorsal to its most ventral section.  
larynx (prompt on "voice box")