Page:American Seashells (1954).djvu/331

Rh in color. lo whorls. Characterized by the numerous, very small, beaded, axial riblets and the thin, gray periostracum. Columella folds 5, the lower 2 being very weak. Nuclear whorls small, smooth and pointed. Commonly dredged from 30 to 333 fathoms. Mitra barbadejisis Gmelin Barbados Miter Plate 26d Southeast Florida and the West Indies. 1 to 1% inches in length, slender, with the aperture wide below and half the length of the entire shell. Characterized by its yellow-brown to fawn color which has an occasional fleck of grayish white. Aperture tan within. Columella with 5 slanting folds. The sides of the spire are almost flat. Weak spiral threads are often present especially in the earlier whorls. A common species under rocks at low tidje. Mitra hendersoni Rehder Henderson's Miter Plate 26c Southeast Florida and the AVest Indies. % to % inch in length, fusiform in shape, with 8 whorls, each bearing a dozen sharp axial ribs which extend halfway down the whorl. Numerous microscopic, spiral cords present. Columella with 4 folds. Color drab pink- ish gray with the upper half of the whorl bearing a wide, lighter, spiral band. Moderately common offshore in several fathoms. Mitra sidcata Gmelin Sulcate Miter Plate 26a Southeast Florida and the West Indies. % inch in length, rather fusiform in shape, with axial ribs as in hender- soni, but without spiral threads. 4 columella folds large and dark-brown. Color of shell dark chocolate-brown with a narrow, white, spiral band on the upper half of the whorl. Moderately common below low-water line under rocks in sand. Do not confuse with Engina tnrhinella which has no columella folds. Mitra albocincta C. B. Adams is probably this species. Mitra idae Melville Ida's Miter Plate 2op Farallon Islands to San Diego, California. 2 to 3 inches in length, heavy, elongate. With 3 columella folds. Color mauve-brown, but usually covered with a thick, finely striate, black perio- stracum. Uncommon offshore.