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Rh Genus Lunatia Gray 1847

Lunatia beros Say Common Northern Moon-shell Figure 22a

Gulf of St. Lawrence to off North Carolina.

2 to 4% inches in length, not so wide; globular in shape; umbilicus deep, round, not very large, and only slightly covered over by a thickening of the columellar wall. Color dirty-white to brownish gray. Aperture glossy, whit- ish or with tan or purplish brown stains. Periostracum thin, hght yellow- brown. Operculum corneous, light-brown and thin. A very common inter- tidal species in the New England area. The t^^ case is a wide, circular ribbon of sand, about the thickness of an orange peel and easily bent when damp. The tiny eggs are embedded in the ribbon.

Lunatia triseriata Say Spotted Northern Moon-shell Plate 22m

Gulf of St. Lawrence to North Carolina.

^ inch in length, similar to young heros but the last whorl usually has three spiral rows of 12 to 14 bluish or reddish brown, squarish spots. The borders of the egg case are crenulated in contrast to the smooth borders of that in heros. This is a moderately deep-water species. Not uncommon from I to 63 fathoms.

Lunatia groenlandica Moller Greenland Moon-shell Plate 22k

Arctic Seas to off New Jersey.

% to I inch in length, 4 to 5 well-rounded whorls. Spire about ^ the total length of the shell. Umbilicus very small, mostly covered over by the callus-like swelling of the top of the columella. Suture fine, deeply indented, bordered below by a weakly raised spiral swelling. Shell white, covered by a thin, smooth, greenish-yellow periostracum. Operculum chitinous, trans- lucent, light-tan, paucispiral. Moderately common offshore.

Lunatia leivisi Gould Lewis' Moon-shell Plate 2411

British Columbia to Lower California.

3 to 5 inches in length, moderately heavy. Whorls globose, slightly shouldered a little distance below the suture. Umbilicus deep, round and narrow. Characterized by the brown-stained, rather small, button-like callus partially obscuring the top edge of the umbilicus. A very common species found in shallow water to 25 fathoms. They are more commonly found in the summer months. Do not confuse with P. draconis.