a, Anus. i, Intestine. r, Nephridium (kidney). r', Aperture of the nephridium. c, Heart. br, Ctenidium (gill-plume). pbr, Parabranchia (= the osphradium or olfactory patch). x, Glandular lamellae of the inner face of the mantle-skirt. y, Adrectal (purpuriparous) gland. t, Testis. vd, Vas deferens. p, Penis. mc, Columella muscle (muscular process grasping the shell). v, Stomach. h, Liver. Entry: K