Black Leather Chitons (Katharina tunicata) are found in the mid-tide zone of surf-swept areas of the rocky coast. Most chitons retreat under kelp, into crevices or under overhangs before daylight, but black leather chitons are not sensitive to light and remain exposed on rocky surfaces during the day. (The Ochre Star looks as though it is going to make a meal out of the leather chitons pictured below, but I think it was actually moving towards some mussels.)
Leather Chitons (also nicknamed Black Katy Chiton) are quite common on the Southern Oregon Coast, and are easily spotted due to their large size...they can grow to almost 5 inches long by the time they are three years old. This chiton has a glossy black leather-like tunic which nearly covers its eight plates...the signature feature of all chitons. The flexibility of these articulated plates, combined with a relatively large sucking foot, allows the chiton to cling very tightly to rock surfaces, and maintain a foothold in even the roughest surf.