^M. undulata.^ A commoner species, perhaps, than either of the preceding, sometimes found on the rocks of sheltered coves at exceptionally low tides. Judging from the number often to be found in the stomachs of fishes, they must be considered excellent food by the cod and its allied species which thrive along the Maine coast. No doubt millions of /M. undulata/ are yearly destroyed in this way. The shell is depressed, with four rounded whorls, a flattish base, and a large umbilical opening. In color it varies from rose-red to brown. The surface is decorated with numerous revolving raised lines placed at uniform distances. Just below the suture the body-whorl is somewhat undulated with short folds. Height three tenths of an inch, base four tenths of an inch. [pg361] GENUS ^Calliostoma^ This genus is better represented on the Pacific coast of the United States than upon the Atlantic. It comprises a series of marvelously beautiful shells, often exquisitely colored. They are regularly conical or pyramidal in shape, with flattened bases. One never tires in the search for calliostomas. They are not common enough to cause one to lose interest, and whenever a good specimen is captured it seems as though one had found some gem cut and polished by nature's skilful hand and prepared for a place of honor in the cabinet. ^C. occidentale.^ The only species of this genus found on the northeast coast. It is larger than /Margarita cinerea/, but somewhat resembles it. It is shining nacreous within and without, and has strong revolving ribs, the upper one on each whorl often being broken into a circular row of white dots. The lip is crenulated. This very pretty species is not likely to be met with upon the shore, but may be dredged in shallow water on gravelly bottoms along the Maine coast. Height about one half of an inch. [Illustration: /Calliostoma occidentale./] ^C. jujubinum.^ A species which occurs in the waters of Florida. Its form is almost that of a true pyramid. The sutures can scarcely be distinguished. The shell is marked by brown and purplish-red spots on a white background, and has numerous revolving ribs broken into rows of white dots like little glazed beads. The umbilicus is funnel-shaped and wide. In Tampa Bay this shell is frequently found on sponges, and may sometimes be gathered on the beach after storms, even as far north as Hatteras. There are as many as twenty species of this genus in American Atlantic waters, but they are either rare or have deep-water stations.