Help Appreciated.

[rainforest]

Hello everyone,
Recently my grandfather gave me a large box of unidentified shells from all over the world, and I'm looking to identify as many as I can.
There's some I'm completely stuck on, though, so any suggestions/information would be much appreciated.


Not sure at all what this is, but I thought I'd try my luck:




That's only a fraction of what's in the box- but I'm starting small