This unique and beautiful Mitre has been already described by Captain Marryat in the Linnaean Transactions: the figures, however, are uncoloured, and give a very indifferent idea of the graceful symmetry of its form. My friend Dr. Leach, with his usual liberality, permitted me to draw the accompanying figure of it at the British Museum, where it is now deposited. It appears to have been taken near Nice in the Mediterranean, adhering to a sounding-line, in very deep water; a very singular locality, since nearly all the Mitres have generally been supposed to inhabit the tropical seas, or at least far from the coasts of Europe. It should, however, be remarked, that _Cypraea lurida_, an Asiatic shell, I have found on the shores of Greece: and C. Ulysses, in his travels in the kingdom of Naples, enumerates several shells as inhabiting the warm shores of the Tarentine Bay, which are generally known only as natives of the Red Sea and Indian Ocean. These facts, with many others, prove the physical distribution of _Molluscae_ to be less decidedly marked than almost any other class of animals. This genus is included with that of _Voluta_ by Linnaeus and our own writers, although long ago justly separated by the continental zoologists. * * * * * Pl. 4 [Illustration] BULIMUS melastomus. _Blackmouthed Bulimus._ * * * * * GENERIC CHARACTER. _Testa ovalis, vel oblongo-ovalis. Spira elevata. Os integrum, sub-ovale. Columella laevis, simplex. Labium externum crassum, reflexum. Internum ultra medium cavo-inflexum. Operculum nullum._ Shell oval or oblong-oval. Spire elevated. Mouth entire, sub-oval. Column smooth, simple. Exterior lip thick, reflected. Interior lip beyond the middle inflected, and hollowed beneath. Operculum none. * * * * * SPECIFIC CHARACTER. _B. testa oblongo-ovata, alba, cinereo marmorata, spirae anfractibus longitudinaliter plicatis, labio exteriore complanato; apertura nigra._ Shell oblong-ovate, white, marbled with cinereous. Spiral whorls longitudinally plaited. Outer lip flattened; aperture black. * * * * * The genus _Bulimus_ was long ago formed by Scopoli out of the heterogeneous mixture of shells thrown together in the Linnaean genus _Helix_[3], &c.: it comprehends some of the larger and most beautiful of the exotic land shells, among which the present species will stand conspicuous both in beauty of colouring and excessive rarity. While travelling among the forests of Brazil, in the province of Bahia, I found the shell here figured one morning on the leaves of a _Solanum_. I not only searched myself, but promised as a reward to any of my Indians who would bring me another, a two-bladed Birmingham knife!--the greatest temptation they could have!--but in vain; for I never saw another before or since.