Aeolidiella oliviae. Went out to Fitzgerald Marine Reserve today with Arch and Jessie, and met up jalbersmead for some 'branch action. We saw plenty of cool stuff, and it was great meeting someone from Flickr in meatspace! Sadly, very few of my pics came out. This DSLR brings about equal parts delight and maddening frustration.
Boy was I excited to find this: Hermaea oliviae! Another sacoglossan for the list. It was in this pool with a ton of other slugs. I didn't see any obvious green filamentous algae around for it to eat.