Page:American Seashells (1954).djvu/127

Rh $1/8$ inch in length, 4 whorls, slightly wider than long, smoothish except for microscopic, weak threads or incised lines. Umbilicus small, round, deep. Exterior grayish brown, commonly with microscopic, brown, spiral lines. Aperture dark-greenish iridescent. Littoral on algae; common.

$1/3$ to $1/2$ inch in length, whorls 5 to 6, upper whorls with 5 to 6 smoothish, small, spiral threads, between or over which are microscopic, axial, slanting threads. Umbilicus a minute chink. Exterior dull, chalky whitish to yellowish gray. Aperture rosy to greenish pearl. Apex usually eroded. A common littoral species in the northern half of its range. Also dredged in 50 fathoms.

2 inches in length, moderately fragile, sculptured with varying number of spiral rows of fairly large beads. No umbilicus. Shell white with a thin, glossy, yellowish-green periostracum. Interior of aperture pearly-white. This is a choice deep-water species much sought after by collectors. Moderately common in 100 to 600 fathoms.

1 to $1 1/2$ inches in length, moderately solid, similar to L. bairdi but with a higher, flat-sided spire. The suture is usually more impressed. Color gray to grayish white. Moderately common from 20 to 350 fathoms.