Chitons & Urchin by marlin harms
Via Flickr:
Another one from the archives. Chitons: left–Tonicella lineata, Lined Chiton or Tonicella lokii, Loki’s Chiton; right–Mopalia lignosa, Wood Chiton or Woody Chiton. Urchin: Strongylocentrotus sp. The chitons were probably near 2" (5cm) long. Montana de Oro State Park, San Luis Obispo Co., CA

Strongylocentrotus droebachiensis “Green Urchin” Echinoidea

Olympic National Park, WA
June 2, 2013
Robert Niese

Strongylocentrotus droebachiensis has one of the longest binomial Latin names of any organism in the world. It is also one of the most abundant and widely distributed urchins on Earth. Here in Washington, S. droebachiensis is at the southernmost extent of its range.