In looking at Snails some key anatomical features need to be noted
The Spire
The spire is the part of the shell above the last body whorl. Long, thin shells have a very tall spire, whereas species like the garden snail have a very short one. The whorls of the garlic and heath snails are almost flat.The Umbilicus
The hole that’s visible on the underside of some of the species,umbilicus is called the Umbillicus It can be seen in snails such as the garlic and heath snail. It is distinctive, but you do have to look at the underside of the snail to see it.