Philine pruinosa from Norway

Dear Erling Svensen,
When I saw your upper photo it reminded me of a drawing I had seen of a Philine with a prominent split in the posterior shield, but it took me a while to find it. It was a drawing by Sars (1878) of an animal from Norway which he identified as Philine pruinosa. Pilsbry (1896) copied Sars's drawing which I reproduce alongside. We can see in the drawing that the parapodia also has relatively small parapodia and a border around the edge of the posterior shield. I can't recall seeing a photo of this before.

One problem with identifying most cephalaspidean bubble shells is that the species were described from the shape of the shell with no information on the living animal. The shell drawn here by Sars looks quite like Clark's shell but from looking at the literature, we know very little about this species. It certainly fits the animal from Norway that Sars called P. pruinosa so I think we will stick with that until specimens from England are better described.

• Pilsbry, H.A. (1896) Manual of Conchology; Structural and Systematic with Illustrations of the Species. [Ed:  G.W.Tryon] Vol. 16, 251pp, Pls 1-71.
• Sars, G.O. (1878) Bidrag til Kundskaben om Norges Arktiske Fauna 1. Mollusca Regionis Articae Norvegiae. Universitetsprogram for foerste halvar 1878: 1-467, Tab I-XVI.

Best wishes,
Bill Rudman