Unusual Shellfish

Unusual Shellfish

Observation - Unusual Shellfish. Description: Amazing creatures! Shells are a Light blue/grey in colour. The soft, tubular body is attached to a washed up tree stump on a west Dorset beach. The body also appears to be far too big to be able to retract into it shell. Live; the bodies were an orangey

Amazing creatures! Shells are a Light blue/grey in colour. The soft, tubular body is attached to a washed up tree stump on a west Dorset beach. The body also appears to be far too big to be able to retract into it shell. Live; the bodies were an orangey/tan colour. Dead and very smelly; the bodies were black. The photo shows the scale against my hand. Any ideas what they are please?