Taken about 60 ft. off of a place called White Rock, north of Guymas. She is about 3/4 of an inch long, taken with extension tubes on the Nikonos. I'm working on getting some images up on Flikr and would like the proper name. These little guys are very localised, but when you find one there are usually 8 to 10 close by.
Any help appreciated.
Steve
That's a baby lettuce slug - Elysia diomedea. Older books will have it as Tridachiella diomedea. It's the Pacific equivalent of the Caribbean lettuce slugs E. crispata and E. clarki.