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The Atoll of Funafuti, Ellice group : its zoology, botany, ethnology and general structure based on collections made by Charles Hedley of the Australian Museum, Sydney, N.S.W.

Thetidos morsura, sp. nov. — (Fig. 42)

Thetidos morsura, sp. nov.
(Fig. 42).

Fig. 42.

Fig. 42.

Shell stout and strongly built, briefly conical, a little turreted, anteriorly narrowed suddenly with a short straight and truncate canal. Whorls five, exclusive of the protoconch. Colour dead white, except the two uppermost whorls and the protoconch, which are pale fawn. Sculpture—the last whorl has ten thick and prominent ribs, round at their base and summit, their own width apart, shouldered posteriorly and abruptly terminating anteriorly at the basal constriction. On each succeeding whorl the ribs alternate with those beneath. The revolving sculpture consists, on the last whorl, of eight, strong, elevated, equidistant, narrow spiral cords which over-ride the ribs, and five such which encircle the base, where vestigial ribs tend to dissect them into nodules; on the penultimate whorl there are four to five cords visible. Protoconch tilted, two-whorled, and spirally grooved. Aperture narrow; columella page 474excavate above, anteriorly ridged by the entrance of three of the basal cords which ascend obliquely; canal open, broad, short, truncated; outer lip much thickened externally by a heavy varix which is crossed and denticulated by the spiral sculpture; within the varix, and at right angles to it, the aperture proper has a second raised lip, and within that again are three large, equidistant tubercles, the largest and most prominent of which is that next the sinus; the anal sinus is moderately deep, scarcely mounts on the preceding whorl, and spreads a callus across two ribs. Length 5½, breadth mm.

One example, procured in eighty to forty fathoms by the tangles, with the preceding species.