Sorry if you were expecting pictures.

Back in Spring I had found some very cheap grapefruit that were like 4 for a buck at a Hispanic supermarket. They had really thick pith that were about the same as the Oro Blanco. From online image searches I see that most grapefruit have thinner pith.

The color was much like a grapefruit; salmon color fruit, blushy skin, bitter taste. But had the thick pith like an Oro Blanco.

Does anyone know what variety that could be?

sounds like pomelo

Pomelo!

The motion has second!

I disagree with the right honourable gentlemen, for pomelos are not bitter (unless you also eat the skin around the segments which is indeed bitter).

Could these have been under ripe grapefruit which had not yet developed their full flesh?

All the pomelos sold here are always under ripe (I'm guessing so their numerous seeds don't grow large and offensive, they pick them when the seeds are only a few millimeters long). They're never bitter unless you eat the segment skin or pith along with the flesh.

We have a second and a motion for discussion. Could we see some pictures please.