"They tap and talk to the seashells."
Here's a breakdown:
* Elles: They (feminine plural)
* tapent: tap (present tense, third person plural)
* discutent: talk, discuss (present tense, third person plural)
* aux coquillages: to the seashells
The phrase implies that there are women who are interacting with seashells, possibly listening to them or trying to communicate with them.