Another undescribed species of this elegant family, and of great rarity, in the private collection of Mr. G. Humfreys. The whole of the body whorl and commencement of the spire is cancellated. The longitudinal striae are crowded, thickened, and slightly elevated, giving a crenated appearance to the suture: the transverse striae slender, and filling up the interstices. The spire is nearly smooth and a little bent: the ground colour very light orange, with three darker interrupted bands on the body: whorl separated by two slender lines of the same colour; the spiral whorls have only two bands and a line between; the upper margins slightly compressed on the suture; the outer lip within smooth. * * * * * MITRA rigida. _Ribbed Mitre__--middle figures._ * * * * * SPECIFIC CHARACTER. _M. testa costis longitudinalibus, elevatis, linearibus, integris, interstitiis laevibus ad basin granulatis; spira producta; columella 4-plicata; apertura brevi._ Shell with elevated, longitudinal, obtuse, entire ribs, the interstices smooth, the base granulated; spire lengthened; pillar four-plaited; aperture short. * * * * * Equally rare, and from the same collection as the preceding. In habit it approaches nearest to _M. exasperata_ of Chemnitz, but has not the ribs angulated or their interstices striated, and is much more narrowed at the base than in that shell, which I have seen: the outer lip is also smooth; the inside strongly striated. This shell was formerly in the collection of Mr. Keate, the elegant author of the "Sketches from Nature." * * * * * Pl. 30 [Illustration] ACHATINA marginata. _Marginated Achatina._ * * * * * GENERIC CHARACTER. _Testa ovata, vel oblongo-ovata, spira elevata, apertura subovale. Columella laevis, simplex, ad apicem truncata; labium externum tenue, internum inflexum integrum; umbilicus nullus._ Typus Genericus _Bulla Achatina_. Linn. Shell ovate, or oblong-ovate; spire elevated; mouth nearly oval. Columella smooth, simple, truncated. Outer lip thin; inner lip entirely inflexed. Umbilicus none. Generic Type _Bulla Achatina_. Linn. * * * * * SPECIFIC CHARACTER. _A. testa ovato-oblonga, strigis inaequalibus ferrugineis; spira ad apicem obtusa, 5-voluta; sutura depressa linea sulcata marginali._ Shell ovate-oblong, with irregular ferrugineous stripes; spire obtuse at the top, of five volutions; the suture depressed, with a marginal indented line. _Lister_ 579. _fig._ 34. _Gualt. pl._ 45. B. _Knorr_, _vol._ iv. _tab._ 24. 1. (badly coloured.) * * * * *