Slippery snails...

Here is a diagram of a snail I thought you might find interesting:

image taken from: http://en.wikipedia.org/wiki/File:Snail_diagram-en_edit1.svg

I should mention that you won't be dissecting your snail!! So all of the labels for inside bits like the lung and kidney can't be added to your diagrams!! But you can look out for things like the respiratory hole, mouth, eyes, tentacles and genital pore!