Valves of dried specimen. Animal length c.15mm. Littoral. Orkney, Scotland. 1974.
Top: end of intermediate valve, part broken.
Bottom: posterior edge of head valve i.
Edge of tegmentum (1) with exposed permeating aesthete canals.
Edge of articulamentum lacking canals (2).
Canals vertically penetrate the articulamentum locally in the slit rays (3) and jugal tract (4), as conduits for branches of the body’s lateral nerve cord conveying stimuli received by the aesthetes on the surface of the tegmentum.