So do I mate but I'd never heard them called that until I met JJ. Must be a totally exclusive mackem word that.
I believe the correct name for them are whelks.. However, I never knew this for many years and always called the willocks..
No mate, whelks are different, much bigger. The correct name is periwinkle, hence the name winkle. That's also where the boots with the pointed toes were called winkle pickers. No matter how much I argue facts Jerry just wont have it like.
I think whelks are the common term for all sea snails.. Periwinkle is as you say is the precise name for the small inshore species that we are talking about..
Billy is spot on I used to eat them with salt and vinegar in the 1960's with a pin ! you had to get the ' eye' out the small black thing first though hehe.