Some of my Shells and shell lookalikes

First thoughts
This is just going to be a personal project with random observations but will comprise quite a lot of Annotated pictures, showing some of the Identification Features of the shells.
I exclusively use PhotoFiltre (Free) for annotations.
http://photofiltre.free.fr/download_en.htm
The photos are mostly taken at home, where I can control lighting and, specially, shadows. I do not use sophisticated cameras, my pocket camera is the preferred one I use in- and out-doors. For the record this is an Olympus Tough TG but really any camera will do. I prefer not to use additional or artificial lighting.
https://www.dpreview.com/products/olympus/compacts/oly_tg3
I sometimes increase the contrast and subdue the midtones to get the best out of texture lighting - again using PhotoFiltre less ↑