newbie request: which story is...

[Luigi Caponetto]

Hello world!

since this is my first posting to the ML (but I had been a curious
reader for about one year) I'd shortly introduce myself: I'm a male,
italian, 32 years old electronics engineer which recently (thanks
to all you people!) re-discovered old and new disney comics.

And now my question.
Suddendly a few days ago, it comes to my mind a story that I've
probably read into some mid-80s *topolino* (the story is written
in italian).

It was about a sort of realm (held by a queen? maybe all the
inhabitants were female?) which is located *under* the sea bed
(not far from duckburg coast).
The only communication way to the outside world is constitued
by a sort of funnel which (under some circustancies?) may appear
above the sea level: the larger end is the part appearing above 
the sea level while the smaller end is directly under the sea bed.