that is median, is connected via conjunctiva
along its proximolateral margins to the stipites, is articulated with the labial palps, is continuous along its distal margin
with the ligula
and distolateral margins with the distal hypopharynx
and receives the site of attachments of the extrinsic labial palp
written by: Vilhelmsen, L., and I. Miko. 2010. Curators/Head..