The features of the structure of the snail shell are important to identification. This section is an overview of the major features of the snail shell. But first, the whole snail body. When you see a live snail, you are missing most of the body - it is inside. You can see the muscular gliding foot and the head with its two pairs of tentacles. The upper pair contain the eyes and the lower pair are general sensory tentacles. The rest of the animal’s organs are inside the shell. This snail is a Polygyrid and you can see the reflected lip with the mantle at the edge. The mantle secretes the shell.
This snail head shot shows the two pairs of tentacles head-on. The upper tentacles house the eyes. The mouth is in between the lower sensory tentacles and just below. It contains a muscular strip of tissue with rasping teeth – called a radula. The snail cruises along scraping the surface and eating what is there.
The body of a slug is out there for all to see and is important for identification to species. On this Giant Garden Slug, you can see the slightly lighter-in-shade spotted mantle at the front (anterior) end and the longitudinally striped body behind. That mantle and the location of the pneumostome (breathing air hole) are among the useful characters for identification. These are covered in the key for slugs.