Shaped, the French think, like a knuckle of ham, and up to 75 cm long, although the market length is much less. The inside of the shell is a pearly yellow. A remarkable feature of the fan mussel is its byssus, or projecting tuft of silky fibres – like the ‘beard’ of the ordinary mussel but much finer. These were collected by fishermen in southern Italy (especially at Taranto) and spun and woven into a fabric from which gloves and stockings were made. The material (lana-pesce, fish wool) was already used in classical times. Patience Gray has pointed out to me that ‘vaporous garments’ made of it are ‘still to be seen on dancing figures in Pompeian frescos’, either dyed purple or with their natural golden lustre. Such garments sound highly desirable. But the practice has almost, if not entirely, died out.
