<p><strong>Fig. 3.45.</strong>&nbsp;(<strong>C</strong>) Sand mason worms (<em>Lanice conchilega</em>) build straight tubes using sand grains and shell fragments.</p>

Fig. 3.45. (C) Sand mason worms (Lanice conchilega) build straight tubes using sand grains and shell fragments.

Image courtesy of Matthias Buschmann, Wikimedia Commons