Large shell collection found

[dcberg00]

Hello all
I am NOT a shell collector, however while clearing out a room in my parents house, my wife and I came across a LARGE shell collection. We have NO CLUE what we have in terms of a collection. We are trying to sort them by common features and think we are doing ok. However, I am not sure how I should present this here on the forum. Is it ok to post multiple photos? Or should we do it in one shot?

A little more background. This collection is OLD. The collection was started by my grandfather when he was a kid, he passed away at the age of 77 in 1981. This collection has not seen the light of day since my grandmother passed away in 1987.

Thanks in advance for any help!