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Show 1878.] FORMOSA AND THE PERSIAN GULF. 729 cimens presented to the Museum by Mr. Dickson, There are two on the penultimate whorl, one at its base, and one a little above the middle. On the body-whorl there are three, the two upper ones being continuous with those on the preceding volution, and the third at the base. MELANIA OBLIQUIGRANOSA. (Plate XLVI. figs. 7 & 8.) Shell elongately ovate, acuminate above, of a dirty yellowish colour, and usually coated with a black earthy deposit; spire acutely conical, with straight outlines; whorls 9-i0, turreted, quite flat, obliquely plicated and spirally ridged, with nodules at the point o'f contact of the plicae with the ridges ; on the whorls of the spire the ridges are four in number, the granules on the uppermost one a little larger than those on the three lower ones. Body-whorl almost flat above the middle; at that point and beneath somewhat convex, encircled by 11 or 12 transverse ridges, whereof 5 or 6 of the upper ones are granuliferous, the rest either uninterrupted or displaying an indication of oblong granulations. Aperture pyriform, acute superiorly, within of nearly the same colour as the exterior, but coated with a thin smooth callous deposit occupying about f of the entire length of the shell; columella considerably arcuated, at the middle white, united above to the lip by a very thin enamel on the whorl; lip thin, sinuated above and prominent below the middle. Length 25 millim., diameter 8; aperture 10 long, 5 wide. Var. monstrosa. Shell ovate; spire short; aperture more than half as long as the shell. Hab. Formosa (Dickson). This species may be recognized among the several allied forms from the Philippine Islands and other places by its very rectilinear acute spire and perfectly flat whorls. The uppermost series of granules is at a little distance beneath the sutural line; and from this circumstance the whorls have a turreted appearance. The nodules of this series are larger and fewer in number than those of the other series, and consequently do not quite regularly terminate the obsolete plicae, upon which the other three granules are situated in an oblique direction. Some of the granules have a squarish form, others are transversely somewhat oblong; and most of them have the upper and lower margins rather straight, with the lateral edges less defined, but gradually blending off into the transverse ridges. The colour of this species is pretty constantly uniform; one specimen, however, is marked with a few reddish dots towards the base, and these are most conspicuous within the aperture. MELANIA TUBERCULATA, Miiller. (Plate XLVI. fig. 9.) Hab. Formosa (Dickson). The shell here figured appears to be inseparable from this remarkably variable and widely distributed species. MELANIA SUBPLICATULA. (Plate XLVI. fig. 10.) Shell rather small, elongate, acuminate, eroded or truncate at the PROC. ZOOL. Soc-1878, No. XLVII. 47 |