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Show 1880.] '^MOLLUSCA OF SOUTH AUSTRALIA. 417 13. RlSSOINA ELEGANTULA, n. sp. (Plate XL. fig. 10.) Shell elongately pyramidal, moderately solid, white ; whorls 8, slightly convex, longitudinally closely and regularly finely plicate, the interstices (especially on the last whorl) crossed by fine lirae; sutures distinct; aperture subovate; outer lip thickened, and slightly sinuous at the base of the columella. Diam. 1, alt. 3 lines. Hab. Aldinga Bay, from shell-sand (Tate). 14. RISSOINA LIRATA, n. sp. (Plate XL. fig. 11.) Shell elongately pyramidal, rather thin, dull milky white; whorls 7, a little convex, longitudinally sculptured with regular moderately distant ribs that become obsolete towards the centre of the last whorl, which is crossed between the periphery and the base with numerous very fine, close-set hair-like striae ; outer lip thckened and variced. Length 2, breadth f of a line. Hab. Holdfast and Aldinga Bays, in shell-sand. 15. COLLONIA (?) ROSEOPUNCTATA, n. sp. (Plate XL. fig. 8.) Shell minute, narrowly and deeply umbilicated, globosely turbinate, solid, white, more or less dotted or flamed all over with bright rose-colour ; whorls 4, convex, closely concentrically ridged throughout; aperture subcircular ; peritreme a little thickened and contracted. ( Diam. 1|, alt. 1\ line. Hab. Holdfast Bay, St. Vincent's Gulf; in shell-sand (Tate). Were it not for its umbilicus, this minute shell in ils general aspect closely resembles a Collonia. If the operculum, when discovered, proves to be calcareous, then its relationship to that genus will be more nearly established. 16. ADEORBIS VINCENTIANA, n. sp. (Plate XL. fig. 9.) Shell depressedly conical, ovate, broadly umbilicated, moderately thin, semipellucid, white; whorls 3, rapidly increasing, the last very large, convex, finely undulately concentrically striated, obtusely keeled below the periphery, and with a basal keel surrounding the umbilical region, which is crossed by somewhat irregular rude lines of growth that become slightly crenate upon the keel; spire small, elevated'; apex papillary; aperture semilunar ; outer lip arcuate, simple ; inner lip nearly straight, sinuously angled posteriorly. Long. 3, lat. 2 J, alt. 1| line. Hab. Aldinga Bay, St. Vincent's Gulf (Tate). About the same size as Adeorbis angasi, A. Ad., from Port Jackson, from which it differs both in form and sculpture. |