Snail roams without shell!

Probably not a snail, but rather a flat worm or type of nudibranch. There are some (stomapods? Maybe...) that have only a very small shell that is usually buried within the mantle. Snails are pretty firmly attached to their shells, and removal from them is fatal.
 
Originally posted by mogurnda
stomatella snail.

Thanks--that's the word I was looking for. Stomapod--sheesh! What was I thinking? And actually--mantis are stomatopods...;)
 
Yep. Nudibranchs have their gills on the outside (hence the name), while sea hares have a very small shell and their gills tucked in a mantle, and stomatella snails have decent sized shell that is hidden by the mantle. They all look similar on the outside, but aren't very closely related.
 
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