The pleated outer lips of the snout can expand widely to help retain food particles loosened by the radula (see ).
There is often an aberrant extra eye. The pear-shaped black pigment of the eye can be discerned through the side of the translucent stalk but only the pinhole narrow end is open to the water.
Menai Strait, Wales, March 2015.
Full SPECIES DESCRIPTION at flic.kr/p/2odgEy1
Sets of OTHER SPECIES at:
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