Photo of apical view of the shell of Clear sundial <i>Architectonica perspectiva</i>.
<a rel="nofollow" class="external text" href="https://www.flickr.com/people/28722516@N02">Richard Parker</a>
CC BY 2.0
<a rel="nofollow" class="external text" href="https://www.flickr.com/photos/28722516@N02/3709701796/">Clear sundial - Architectonica perspectiva</a>. Uploaded by <a href="//commons.wikimedia.org/wiki/User:JoJan" title="User:JoJan">JoJan</a>. Rotated, cropped and border removed by <a href="//commons.wikimedia.org/wiki/User:Snek01" title="User:Snek01">User:Snek01</a>.