T. hotessierana Orbigny from the West Indies is similar, but rarely over 1⁄3inch, with a more rounded periphery, with smaller, neater, equal-sized, smooth spiral threads, and dark bluish black in color, except for a whitish area around the narrow umbilicus. Uncommon.
Florida Keys? Caribbean area.
1⁄2 inch in length and width. Characterized by its bluish-gray color, corrugated sculpture (weak spiral cords and oblique lines of growth), its concave base, thin outer lip, and especially by the blue-green to iridescent-green circle of color around the very deep, round, narrow umbilicus. A variant exists in some areas which lacks the green, umbilical color and in which the spiral cords are stronger and the shell with axial, slanting bars of black-brown. Very common in the West Indies, along the rocky shores.
Vancouver, B. C, to Lower California.
1 to 11⁄2 inches in length, heavy, dark purple-black in color; smoothish, but with a narrow, puckered band just below the suture. Weak spiral cords rarely evident; coarse growth lines present in large, more elongate specimens. Base rounded. Umbilicus closed or merely a slight dimple. Columella pearly, with two small nodules at the base. A very common littoral, rock-loving species. Do not confuse with T. gallina.
Plate 18v
San Francisco to the Gulf of California.
1 to 11⁄2 inches in length, very similar to funebralis, but a lighter, grayish green color with dense, zigzag, axial stripes of purplish. The shell surface is also coarser. A common, southern species found among littoral rocks.
Crescent City to Santa Barbara Islands, California.
1 to 11⁄2 inches in length, similar to funebralis, but light chestnut-brown in color with the base often glossy, brownish white. The umbilicus is closed, but usually with a dimple-like impression. Columella usually with only one small tooth near the base. Common at dead low tide on rocks. Usually heavily encrusted with algal growths.
