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Show 1882.] MOLLUSCAN F A U N A O F M A D A G A S C A R . 383 paler towards the apex, where the epidermis is mostly worn off, leaving a white surface ; last whorl indistinctly transversely zoned and lineated with dark brown. Volutions 7, rather convex, regularly increasing, longitudinally striated by the lines of growth, which are more or less puckered beneath the suture, and at times somewhat wrinkled through being crossed by a few obsolete transverse striae. The extreme upper edge of the whorls is yellow at the suture. Body-whorl scarcely descending in front. Aperture inversely auriform, blue within, occupying three eighths of the entire length of the shell. Outer lip thickened within, dirty whitish. Inner lip of the same colour, thickened also, narrowly expanded in the umbilical region, joined to the labrum above by a thin callus. Length 53 millim., width 21 ; aperture 20 long, 11^ broad. Hab. Near the river Anonive, about fifty miles south of the capital, Antananarivo (W. Johnson). This species might be regarded by some as a dwarf form of S. eximia, Shuttleworth ; but, besides size, there are other distinctions. Mr. Johnson says he never could find the larger species at the above locality, nor did he ever meet with the smaller one in company with it elsewhere. As the last whorl in the present species scarcely descends at all, the suture is less oblique than in S. eximia; the surface is less puckered by transverse striae, the breadth of the shell is greater in proportion to its length, the last whorl is less cylindrical, the columella is not so broadly reflexed or flattened in front, and the aperture is narrower at the base. MELANATRIA JOHNSONI, sp. nov. (Plate XXII. figs. 6, 7.) Shell large, elongate-pyramidal, turreted, thick, covered with an olive epidermis, closely lineated or strigate with longitudinal lines of a darker tint. Whorls - ?, the remaining nine excavated at the upper part, very slightly convex beneath, strongly spirally ribbed and grooved. The ribs are six in number on the upper whorls and rounded; the two above are much more slender than the four beneath; the uppermost borders the suture; the next lies in the concavity at the top of the whorls; and the rest surround the slight convexity, and are three times as broad as the sulci separating them. All the whorls, with the exception of the last four, are coronated at the slight angle below the excavation with very short, hollow, oblique spinules; and some of the spiral grooves exhibit rows of fine granules. The last whorl descends somewhat, giving the shell a slightly distorted appearance ; it is girded with about twelve transverse costae, a few at the base being smaller than five principal ones around the middle. The aperture is bluish within, faintly stained with olive-brown near the margins. Peristome widely and deeply sinuated on the outer lip in the concavity of the whorl, arcuate and prominent in the middle, then shallowly sinuated again (vide fig. 7). Columellar margin thickened, free, arcuate, reflexed, ending in a distinct basal sinus. Length 78 millim., diam. 24; aperture 24 across diagonally, and 16 in a transverse direction. PROC. ZOOL. Soc-1882, No. XXVI. 26 |