Shell thick, sub-involute, diconic, or ventricose, terminated like a cone before and behind; aperture very long, narrow, terminated anteriorly by a canal more or less elongated, recurved; the edges parallel; the external dilating with age, offering behind a gutter at its attachment to the spire, and before a sinus more posterior than the canal, through which passes the head of the animal; operculum horny, long, and narrow, with elements as if imbricated; the summit terminal. Strombus gigas. S. accipitrinus. S. latissimus. S. tricornis. S. Canarium. S. Isabella. S. vittatus. S. epidromis. S. gallus. S. bituberculatus. S. cristatus. S. dilatatus. S. bubonius. S. lentiginosus. S. auris-Dianæ. S. pugilis. S. pyrulatus. S. gibberulus. S. Luhuanus. S. Mauritianus. S. colomba. S. succinctus. S. troglodytes. S. tridentatus. S. urceus. S. plicatus. S. Floridus. S. papilio. S. lineatus. S. marginatus. S. turritus. S. cancellatus. _S. polyfasciatus._ The many-banded Strombus. Pl. 28, fig. 2. Species distinguished by its bands, and by having the margin of the outer lip thickened. _S. auris-Dianæ._ Diana’s Ear Strombus. Oblong-ovate; spire acute, tuberculated, and transversely striated; base recurved, outer lip thick, anterior lobe with a finger-like termination. _S. pugilis._ The fighting, or thick-spined Strombus. Anterior lip prominent, rounded, smooth; spire crowned with spines, the outermost whorl cancellate; columella much reflected; beak three-lobed, obtuse, flesh-coloured, and polished within. FAMILY XVIII. PURPURIFERA. Eleven genera. 1. Cassidaria. Five species. Marine shell, sometimes confounded with the Cassis, but distinguished by the canal which terminates the aperture being ascendant, very little arched, and not suddenly recurved. Shell sub-globular, ventricose, tuberculated, or fluted; spire short and pointed; aperture long, oval, sub-canaliculated anteriorly; the right edge effuse and folded back; the columella covered over with a broad, smooth callosity, uniting behind to the right edge; operculum horny.