On the Structure and Adaptations of Pandora inaequivalvis and P. pinna

The two British species of Pandora are adapted for life on muddy-sand. P. inaequivalvis is taken from very sheltered shores at low-water mark and down to 10 fathoms. P. pinna is taken from depths of over 40 fathoms. Both species are markedly inequivalve. This is probably connected with the habit of lying horizontally. The mantle muscles and the ciliary mechanisms of the mantle and gills are described. An account of the morphology and the functioning of the stomach is given and various modifications, due to the reduced typhlosole, are described.