Phyllidiella annulata? from Mauritius

Note added 7 November 2002: I have identified this as P. meandrina. - Bill Rudman

Dear Erwin,
My first thoughts were yes it is Phyllidiella annulata but on reflection I think it is a peculiar form of P. pustulosa in which some of the central clusters of tubercles have formed into rings. I'm afraid it all comes down to a question of definition. Brunckhorst compares the two species and says that in P. annulata there is a distinctive colour pattern of pink rings with, small low tubercles, on a black background. There is no central tubercle to each ring. He says P. annulata lacks the compound tubercles and tubercular clusters found in P. pustulosa. P. pustulosa also has a thin pink mantle border.

If this is so, then this animal doesn't fit the definition of P. annulata. I don't like saying 'something doesn't fit the definition' because 'definitions' are man-made and need to be changed if they don't fit the 'facts'. However, although this photo certainly looks like an intermediate between the two species, I think we would need further information to be sure. All I can say is that if the two are good species then I would guess that this animal is a from of P. pustulosa.
Bill Rudman.