Page:American Seashells (1954).djvu/305

Rh gausapata Gould (California to Alaska) is similar, but without the swollen shoulder. Genus Mitrella Risso 1826 Subgenus Astyris H. and A. Adams 1853 Mitrella lunata Say Lunar Dove-shell Plate 25gg Massachusetts to Florida, Texas and the West Indies. %6 to M inch in length, glossy, smooth, translucent-gray and marked with fine, axial zigzag brown to yellow stripes. Base of shell with fine, in- cised spiral lines. Aperture constricted, slightly sinuate. Outer lip with 4 small teeth on the inside. No prominent varix. Nuclear whorls very small and translucent. Color sometimes milky-white or mottled in brown. A very common species found at low tide. Mitrella raveneli Dall Ravenel's Dove-shell Plate 25CC North Carolina to both sides of Florida. % inch in length, resembling lunata, but translucent-whitish, without the mottlings, normally a slightly larger shell, more elongate, with a longer siphonal canal, and with a rather thin outer lip which lacks the deep sinua- tion found in the upper portion of the outer lip as in Iwiata. Commonly dredged from 5 to 90 (rarely to 200) fathoms. Rarely washed ashore. Mitrella tuberosa Carpenter Variegated Dove-shell Alaska to the Gulf of California. /4 inch in length, slender, with a narrow, pointed, flat-sided spire. Shell smooth and usually glossy. Outer lip slightly thickened and with small teeth within. Color a translucent yellowish tan with opaque, light-brown flammules and maculations. Sometimes all brown with tiny white dots. Early whorls in worn specimens have a lilac tinge. Periostracum thin and translucent. Common in shallow water; 7 to 30 fathoms. M. variegata Stearns may be this species. Genus Amphissa H. and A. Adams 1853 This genus was formerly placed in the family Buccinidae. Amphissa versicolor Dall Joseph's Coat Amphissa Figure 50a Oregon to Lower California.