Animal. See Purpura, hereafter.

Shell. Oval or globular, wrinkled; spire middling and pointed; aperture wide, ovate, grooved, and sometimes canaliculated anteriorly; the right edge concave and trenchant; the left nearly straight and marked in the middle with two or three folds; operculum horny. Inhabits the Indian Ocean. One species only is found in America. Forty-nine living species. Twenty fossil.

5. Genus Fasciolaria. Pl. [XI].

Animal. Entirely unknown.

Shell. Separated from the Murex on account of having no varix fusiform or subfusiform; spire middling; aperture oval, elongated, nearly symmetrical, terminated by a rather long, straight tube, the external edge trenchant, the columellar edge having two or three oblique folds. Inhabits the Indian Ocean and Mediterranean Sea. Eight living species. Seven fossil.

6. Genus Fusus. Pl. [XI].

Animal. Entirely unknown.

Shell. With an epidermis, wrinkled, fusiform or dilated in the middle, prolonged posteriorly by the spire, and still more so anteriorly by the canal; aperture oval; the columellar edge straight or nearly so, the exterior trenchant; a horny and oval operculum. Inhabits the Indian and American seas. Forty-six living species. Thirty-seven fossil.