Caption:
Noble pen shell or fan mussel, Pinna nobilis 1,3, critically endangered, and rough pen shell or spiny fan-mussel, Pinna rudis 2. Handcoloured steel engraving by du Casse after an illustration by Adolph Fries from Felix-Edouard Guerin-Meneville's Dictionnaire Pittoresque d'Histoire Naturelle (Picturesque Dictionary of Natural History), Paris, 1834-39.