Adaptation

 

Snails in general have many adaptations but it is believed that they actually still have many of their ancestral characteristics(FWGNA).
Gills:
 Respiration no longer is accomplished by gills- they use their mantle cavity which acts like a lung(E How snail adaptations).
Tentacles:
They have 2 sets of tentacles. The larger 2 have eyes at the base of the  tentacles and the smaller ones are used to feel around their habitat(Animal Diversity Web).
Locomotion:
They have a "foot", gastropod means "stomach footed" that is covered with mucus which protects it from injury and friction while moving along rough surfaces( E How snails adaptations).
Radula:
This is like their tongue, but it is made of a chitinous band with minute horny teeth that tear at what is being sampled. It looks similar to a cats tongue(Animal Diversity Web)

                            
The picture above is of a snail using it's radula on the side of an aquarium.

The above picture is of an actual Fossaria obrussa shell.