1. Berthella plumula. Length 13 mm. Reticulation on mantle resembles lobules of Oscarella (encrusting sponge). Dull orange viscera indicate position of shell. Large transparent central spot resembles osculum of Oscarella. LWS. Menai Strait, Wales. March 2011
2. Berthella plumula. Length 13 mm. Reticulation on mantle resembles lobules of Oscarella (encrusting sponge). Dull orange viscera indicate position of shell. Large transparent central spot resembles osculum of Oscarella. LWS. Menai Strait, Wales. March 2011

Berthella plumula. Length 13 mm. Reticulation on mantle resembles lobules of Oscarella (encrusting sponge). Dull orange viscera indicate position of shell. Large transparent central spot resembles osculum of Oscarella. LWS. Menai Strait, Wales. March 2011