Phyllidia carlsonhoffi from Phoenix Id

Dear Mary Jane,
This is another interesting find. It has similarities to two species described by Brunckhorst, Phyllidia carlsonhoffi and Phyllidia madangensis. Both are described as having cream or white tubercles with yellow tips. Your photos clearly help to expand the definition of at least one of those species to bluish tubercles. Externally there seem to be two quite distinctive differences. In P. madangensis there is a small white tubercle on the front edge of each rhinophore pocket, not directly in front of the rhinophore but situated towards the midline of the body. The other difference is that the sole of the foot does not have a dark median line. In comparison, Phyllidia carlsonhoffi does not have a tubercle in front of each rhinophore and does have a dark median line on the sole of the foot. It is also described as having small white tubercles alternating with the larger coloured ones.

Your photos match Phyllidia carlsonhoffi very well. All we need to do is modify Brunckhorst's definition of the species to include bluish tubercles.

Another very useful bit of new information.

Best wishes,
Bill Rudman.