Page:American Seashells (1954).djvu/165

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TROCHIDAE
115

34 to 1 inch in length, heavy for its size; whorls angular, with the upper third slightly concave to flat and the somewhat angular periphery flattish. Early whorls with minutely beaded threads, later whorls with fine, smoothish cords of various sizes. Nucleus tan to whitish. Color yellowish brown with a few spiral lines of alternating brown and white bars. Sometimes axially variegated. Dredged just offshore from 8 to 35 fathoms. Moderately common.

Calliostoma gemmulatum Carpenter
Gem Top-shell
Figure 33d

Cayucos, California, to the Gulf of California.

34 inch in length, not as wide; characterized by its dark gray-green color and two extra-strong, beaded spiral cords. There are also 3 or 4 minor cords that are not so heavily beaded. Nucleus dark-tan. Moderately common in the littoral zone on rocks and wharf pilings.

Calliostoma supragranosum Carpenter
Granulose Top-shell
Plate 18s

Monterey, California, to Lower California.

12 inch in length, solid, glossy; characterized by numerous, fine, spiral cords which are sometimes weakly beaded, and by a wide, rather flattish periphery. Nucleus tan. Color light yellowish brown, commonly with a spiral row of subdued white spots at the lower periphery. Interior brightly nacreous. Moderately common on rocks at low tide.

Calliostoma annulatum Solander
Ringed Top-shell
Figure 33f

11 to 1+14 inch in length, not quite so wide; characterized by its light weight, golden-yellow color with a mauve band at the periphery, and by the numerous, spiral rows of tiny, distinct beads (5 to 9 rows in the spire whorls). Nucleus pink. Dredged offshore and occasionally washed ashore. Formerly C. annulatum Martyn.

Calliostoma canaliculatum Solander 1786
Channeled Top-shell
Plate 3q; figure 33h

Alaska to San Diego, California.

1 to 1+12 inches in length, not heavy, sides of whorl flat. Periphery of the last whorl sharp. Base of shell almost flat. Characterized by sharp, prominant, slightly beaded, spiral cords. Color yellowish tan. Nuclear whorls white. Moderately common offshore. Found on floating kelp weed. Formerly known as C. canaliculatum Martyn, and doliarium Holten 1802.