fauces

noun[usually plural]3

1. •
   The narrow passage from the mouth to the pharynx, situated between the soft palate and the base of the tongue.
2. •
   The throat of a calyx, corolla, etc.
3. •
   That portion of the interior of a spiral shell which can be seen by looking into the aperture.

   • There are two orange-coloured spots at the fauces of that Cypraea Isabella, whence its name, orange-tip. — 1826