fauces
The narrow passage from the mouth to the pharynx, situated between the soft palate and the base of the tongue.
The throat of a calyx, corolla, etc.
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 Cypræa Isabella, whence its name, orange-tip.
Where it comes from
Borrowing from Latin faucēs (“the upper part of a throat”).
Adapted from the Wiktionary entry fauces (CC BY-SA 4.0).