Nudibranch Flabellina affinis

Flabellina affinis

This species differ in having an opaque purple band just below the ceratal tip. You can see it clearly in your photo, which would make it Flabellina affinis. The ceratal groups in your photo don't seem to be on such obvious basal stalks but I suspect they are very contracted in this photo.
In this photo you can also see the fine rings on the rhinophores. They are also present in F. ischitana but are not so clearly seen in your earlier photo. The two white sausage-shaped structures behind the first ceratal clusters are in fact the egg sacs of a parasitic crustacea living in the body cavity of the aeolid.
Bill Rudman
Australian Museum, Sydney.