I find websites telling me that many but not all sea snails are edible. I'm wondering if the Ramshorn variety is edible?
My understanding is that "edible" snails are those with substantial enough muscles in their foot to make them worth eating as a delicacy. There are a few sea snails that are poisonous, such as Cone Snails, but I do not think any land snails are. Therefore all land snails are technically edible.
The primary risk when preparing and eating land snails is parasites, particularly nematodes. These will be killed by cooking so make sure the whole snail is well heated through. The gut contents may include poisonous plants, but you do not want to eat that anyway.