The Heath’s Dorid seems to be a little more difficult to find than the other two “sea lemons” — Monterey Dorid or Noble Sea Lemon. It is generally smaller, has a more semi-circular opening around the gills and smaller tubercles.  Not sure why, but these critters always seem to be a bit flat and ragged looking.  They come in white and pinkish as well as the more common yellow — and one of their general features is a brownish tinge to the mantle and fairly low tubercles.  These get up to 2 inches or 50 mm — much smaller than the mature Monterey Dorid or Noble Sea Lemon that can reach 18 and 25 mm respectively.