Verruca stroemia is a small, asymmetrical, sessile barnacle characterized by a flattened, gray, box-shaped shell. One of its distinguishing features is the operculum, formed by a large tergum and a smaller scutum joined together to function as a single, hinged cover. This cover opens along the straight edge of the barnacle’s slanted, D-shaped opening. The shell itself is made up of four plates: the rostrum, carina, tergum, and scutum.