iPhone failed to focus, so photo is a pretty disappointing one of a cool worm. ID from matching description in Morris, Abbott, and Haderlie, but knowing the variability of this phylum and acknowledging the lack of detail in the image, my certainty is not complete. This species has not been recorded at the reserve, until it was uncovered by a visiting class the day before I found this one in a separate intertidal location. See this link for a discussion of similar species that overlap further south: http://biology.fullerton.edu/biol317/ftm/ft_s15_ac_4_17_15.html Small Mopalia visible at lower right.