MITRES; these are usually considered as a genus, or branch of the Volute family; the scientific name is _mitra_, the form is generally long, slender, and pointed—something like the bishop’s mitre, hence the common name of the genus. In the Episcopal Mitre, (_M. episcopalis_,) Plate VI, Fig. 1, we see this form in its greatest perfection; this is a handsome shell found in the Indian seas, and on the coasts of the South Sea Islands. The mollusk is remarkable for a long proboscis, double the length of the shell, the extremity of which swells into a club form, and has an oval orifice or opening: the specific name _episcopalis_, comes from the Latin, and means of, or like a bishop. The Tanned Mitre, (_M. adusta_,) from the Latin _adustus_—burned or parched, is, what is called fusiform and turretted, that is, shaped like a spindle, and having a spire or turret-like termination. The streaks of colour are transverse, that is, running the length of the shell, or in other words, they are longitudinal; this, too, comes from the South Sea Islands. Fig. 2 is the Wrinkled Mitre, (_M. corrugata_,) from the Latin _corrugo_—to wrinkle; it is very different both in shape and markings, from the last species; the whorls, it will be seen, are angulated or pointed above, and the lower part of the shell is much larger than the spiral or upper portion. It is a true mitre nevertheless, although not just such a one as a bishop would like to wear. It inhabits the Indian Ocean, the coast of New Guinea, etc. OLIVES; these, for richness of colour and brilliancy of effect, will bear comparison with any genus of shells. Naturalists speak of them collectively as _Olivinæ_; they belong to the Volute family, and are said to number about eighty species. Most of those which have reached this country, have come from the Mauritius, where they catch them with lines baited with portions of Cuttle-fish. We have here depicted two of them, namely, the Figured Olive, Fig. 3, (_Oliva textilina_,) from the Latin _textilus_, which is woven or plaited; and the Ruddy Olive, Fig. 4, (_O. sanguinolenta_,) from _sanguis_—blood. We must now bring our notice of the Univalves to a conclusion; there are several genera, and many very curious and beautiful species which we have been unable to notice at all, and of those which we have, a short account only could be given; sufficient however, as we trust, to interest our readers in the subject, and induce them to continue the study of it into larger works. Before leaving this division of shells, we would call their attention to one of its greatest ornaments, that is the Ventricose Harp Shell, (_Harpa ventricosa_,) from the Latin _ventriculus_—the stomach, applied to this shell on account of its swelled or inflated shape. Nothing, however, can be more elegant than the whole form, nor more beautiful than the markings of this lovely species, (see Plate VI, Fig. 5,) which belongs properly to the Whelk family. COWRIES.