Bought me a little tub of whelks

From The Road to Little Dribbling: Adventures of an American in Britain by Bill Bryson. Page 118.

Later that same day this lovely young English girl, this person in whom I was about to entrust my permanent happiness and well-being, took me to a seafood wagon and bought me a little tub of whelks. If you have never dined on this delicacy, you may get the same experience by finding an old golf ball, removing the cover and eating what remains. The whelk is the most flavourless and indestructible thing ever to be regarded as a food. I think I still have one of them in a jacket pocket somewhere.