This is another orange-spotted Haminoea similar to H. ovalis. The upper specimen measured 13mm stretched out and was under a chunk of dead coral on a Kwajalein Atoll lagoon reef at a depth of 3m on 29 December 2009. These look like they could be Haminoea sp. 1 on the Sea Slug Forum.
The two photos below appear to show a young specimen from Kwajalein Atoll..
Created 5 January 2009
Updated 22 January 2009