Cylindrical, columella not smooth, but irregularly plaited or wrinkled, and the tooth does not extend within the interior of the whorls as in the other species, but appears affixed only to the edge of the lip; volutions flattened in their upper edges; transverse spiral brown bands. 6. Concholepas. One species. Formerly considered a Patella, but distinct from it on account of having an operculum. It is particularly distinguished by having two teeth at the base of the right side. Shell wide, rough, oval, spire very short, not projecting; aperture very large, oval, effuse, sloped anteriorly; the edges united; the right or external very thick, dentated; the two teeth which limit the slope are a little larger than the others; muscular impression visible, and almost in form of a horseshoe; operculum horny and rudimentary. _C. Peruvianus._ The Peruvian Concholepas. Pl. 28, fig. 1. The type of this genus; exterior dark brown, interior white. 7. Harpa. The Harp Shell. Eight species. This genus of shells is truly beautiful; it was classed by Linnæus with the Buccinum, but Lamarck considered that they were, for their beauty, worthy of forming a genus by themselves. Shell oval, inflated, rather thin, with longitudinal parallel ribs, formed by the preservation of the thickening of the right margin; the spire very short, pointed, the last whorl much longer than all the others together; aperture large, ovate, widely notched anteriorly; the right edge much excavated and thickened outwardly; the columella smooth, and terminated in a point anteriorly. Harpa imperialis. H. ventricosa. H. conoidalis. H. nobilis. H. articularis. H. rosea. H. minor. H. striata. _H. imperialis._ The imperial Harp. Species in which the number of ribs far exceeds that of any other, and occasions it often to be called the many-ridged harp; a small spiral keel round the summit. A rare and valuable species. _H. nobilis._ The noble Harp. Pl. 29, fig. 2. A regular species. _H. rosea._ The roseate Harp. Oblong-ovate; flesh coloured, with roseate interrupted bands; ribs remote; columella of a fine rosy hue. 8. Dolium. The Tun Shell. Seven species. The shells of this genus are generally large, thin, and globose, with a wide aperture, and toothed or crenated outer lip; they have a brittle and light structure, and although some of them grow to a very large size, they retain their characteristic fragility and thinness.