graces_field_journal's Identifications

Several small purple barnacles amongst the numerous grey ones. Image three shows two side by side that are the same size and would have experienced the same level of erosion. They clearly look very different so I they must be different species - hence the huge discussions here and here. Image four is a larger part of the assemblage with many individuals of the two species and what would appear to be a single individual of a third species off to the right.