Subspecies diegensis, according to G. Jensen's 2014 "Crabs and Shrimps of the Pacific Coast, p. 34. Found under a rock. For video, please see this crab's photobomb appearances as he runs laps in the dish throughout my sea cucumber video: http://youtu.be/eFSqBGbKn0c
Not at all certain of this one! Could also be just the "gastrovascular branches" of a sea nettle (no bell or stinging tentacles).
About 6" across. Found washed on top of sea grass, no movement -- perhaps recently dead. Gelatinous, looping/wavy tentacle-like structures attached to a darker-yellow center (just off center in this photo). No obvious organs, etc.
Have been tracking this one for about 6 months - only one in its neighborhood - never strays far from the bat cave.