Ovula oviformis. O. angulosa. O. verrucosa. O. hordacea. O. spelta. O. birostris. O. lactea. O. carnea. O. triticea. O. gibbosa. O. acicularis. O. volva. _O. volva._ The Weaver’s Shuttle. Pl. 34, fig. 4. Species in which the right edge is not thickened or dentated, and with each extremity elongated, producing a long, straight tube, which increases with age. One of the most rare shells of this genus. _O. oviformis._ The egg-shaped Ovula. Pl. 34, fig. 1. Species ovate, much inflated, ventricose in the centre, very glossy and white; right edge dentated, the tube of each extremity very prominent; interior of aperture reddish purple. _O. gibbosa._ The belted Ovula. Pl. 34, fig. 2. Species gibbous, neither end dentated; tubes little marked, and with the body of the shell encircled by a blunt keel. _O. verrucosa._ The warty Ovula. Pl. 34, fig. 3. Species in which the right end is dentated, with a notch and a knob above at each extremity. 2. Cypræa. The Cowrie. 68 species. This genus derived its name from the Cyprian goddess, on account of the beauty of its polished shells. They are generally smooth, of great brilliancy of colour, and elegantly marked with dots, zigzag lines, undulations, or stripes, and covered with an enamel-like glaze. They are found buried in the sand at the bottom of the sea, and are covered by the animal with a thin membrane, which preserves the polish and prevents other testaceous bodies from adhering to them. This membrane consists of two parts, and arises on both sides of the shell in the form of wings, furnishing the testaceous and colouring matter; in some species they do not quite meet on the back of the shell, and the uncovered space is marked by a coloured dorsal line; when these membranous wings overlap each other, this line is nearly obsolete. These shells often differ much with age; at first in thickness, then because the edges are thin, sharp, hardly dentated, unless internally; and, lastly, sometimes in the outline; this is because the two lobes of the mantle, by turning over the primitive shell during the creeping of the animal, deposite new calcareous matter. De Blainville cannot admit the hypothesis of Bruguiere, that these animals can completely abandon their shell to form a new one.