There is a large ramshorn, called the Bolivian ramshorn that has brown stripes running the length of the shell that is a notorious plant eater. It gets a little over an inch in diameter. I think this is a picture of one.
Southerndesert (or anyone else who can answer),
So wait... the new Tylomelania snails eat plants? I've heard that they were generally plant-safe, and too heavy to climb up most plants to eat them anyway.