Sakuraeolis enosimensis mating

Thanks Jun,
I was preparing a close-up photo to show the copulatory organs more clearly when I noticed the strange swellings I have marked alongside as ??. They seem to be on the side of the body between each clump of cerata. Can you see them on any of your other photos? I have no idea what they are.

But while I have made the close-up here are some details about the reproductive system. Being hermaphrodites, both partner has a penis and a vagina, and usually during copulation both partners exchange sperm. However in this case the animal on the right of the photo is acting only as a female.
1 marks the unused penis of the right animal. One of the anatomical characteristics of the genus Sakuraeolis are the elaborate secondary structures associated with the penis, and although difficult to see here, the flap on the left of the penis is part of these secondary structures.
2 is the vagina, or genital opening of the right animal
3 is the penis of the left animal. It is inserted in its partner's vagina, and the whitish line visible through the wall of the pebnis is the muscular sperm duct.
Best wishes,
Bill Rudman