Page:American Seashells (1954).djvu/176

126 $1/4$ inch in length, equally wide, very thick-shelled, resembling in shape a Margarites. Pure white in color. Whorls rounded, 5 to 6 in number, each bearing 5 to 6 strong, rounded, spiral cords, the lower 2 being below the periphery of the whorl. Aperture and parietal wall glossy, slightly opalescent. Columella arched, with a small tooth in the middle and a smaller one usually at the base. No umbilicus. Commonly dredged from 35 to 450 fathoms.

H. linnei Dall from southeast Florida to Barbados has 8 smaller, beaded spiral cords on the upper part of the whorls and 10 on the base, otherwise it is very similar to albida. It is quite rare.

$1/4$ to $3/8$ inch (5 to 9 mm.) in length, solid, globose. Pinkish red to brownish red in color. Last whorl and base with 15 to 20, evenly sized, smooth, spiral cords separated from each other by a space about half as wide as the cords. Base of pearly columella with 2 or 3 exceedingly weak nodules. A very common species frequently washed ashore and inhabited by small hermit crabs from Monterey to Mexico. Do not confuse with lurida.

$1/4$ inch (5 to 7 mm.) in length, similar to carpenteri, but half as large, black-brown in color, although occasionally whitish with red axial streaks. The spiral cords are usually fewer in number and more rounded. Moderately common in shallow water under rocks.

$1/4$ inch or less in length, similar to carpenteri but with a flatter spire, and smoothish, except for numerous incised, spiral lines producing very weak threads. Color dark, rosy-brown. A moderately common shallow-water species, sometimes found with carpenteri. A thorough anatomical and life history study of this genus is needed to ascertain the validity of these species.