Some features below are more discernible in Alder and Hancock’s drawing in .
The colourless, virtually transparent mantle reveals, embedded within it, very long, glistening, glass-like spicules arranged transversely on the dorsum (1), diagonally on the sides (2) and radially at the anterior (3).
Small reddish brown spots are arranged in about six lines on the dorsum (4) and about three concentric lines around the flanks (5).
The unobtrusive anal papilla is surrounded by a circle of up to twelve small, unipinnate gills (6).which are so transparent as to be almost invisible save for a partial faint yellowish or pale orange tint.
Below the mantle, the orange brown digestive gland and other white viscera are discernible. Alder and Hancock (1845-55) stated that this was the only species of dorid in which they could see the internal eyes when adult, but they are concealed on this one.
Length 4 mm. Menai Strait, Wales. September 2011.