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Show 720 MR. E. A. SMITH ON SHELLS FIIOM LAKE NYASSA. [Nov. 6, This species is remarkable for the subgranose plications on the whorls, and the brown carina of the body-whorl. It is difficult to describe in a few words the colour of this interesting form. The general appearance is livid, inclining to yellow or very pale olive ; one shell is livid, with the upper margin of the whorls reddish. The callous band is quite conspicuous only about halfway around the body-whorl, and then gradually fades away, and is only noticeable further up the spire by slightly obliterating the lower extremities of the longitudinal ribs. Two not quite adult specimens were collected by Dr. Kirk at the delta of the Zambesi River, and were placed in the British Museum by Earl Russell. 2. NATICA ANTONI, Philippi. Natica antoni, Philippi, Zeitschrift fiir Malakozool. 1851, p. 48; Krister's Conch. Cab. p. 144, pl. 19. f. 18. Hab. Mouth of the Macusi River, near Quilimane, E. Africa. Nothing can he added to Philippi's excellent description of this interesting species ; but I may mention that a young specimen has a distinct pale zone around the middle of the last whorl, between the two series of brown spots, which are more or less obsolete in the adult shell, and that its umbilicus is quite filled up with the callosity, even in the immature condition. The operculum is shelly, white exteriorly, except near the nucleus, where there is a small pale brownish callous deposit. The surface is smooth and shining, sculptured with the lines of growth, and a single distinct striation parallel with the outer edge, thus marking off a separate margin. From the nucleus a short ridge or rib extends itself towards the centre. The inner or under surface is clothed with a thin, pale yellow epidermis. 3. TELLINA OPALINA, Chemnitz. Tellina opalina, Chemnitz, Kiister's Conch. Cab. p. 172, pl.35. f. 8. Tellinides rosea, Sowerby, Gen. Rec. and Foss. Shells, f. 1. Tellina pianissimo, Anton ; Philippi, Abbild. i. pl. 2. f. 2; Thesaurus Conch, f. 197; Conchol. Icon. pl. 13. f. 58 a, b. (Non T. opalina, Sowerby, Conch. Icon. sp. 258, f. 258 a, bi) Hab. Mouth of the Macusi River, near Quilimane, E. Africa. Only a single specimen, which apparently belongs to this species, was collected. It differs from the normal form in being rather more equilateral. It is pale rose-colour, almost white at the umbones, and at the ligamental area; and the internal raised radiating ribs are well defined. The name opalina, proposed by Sowerby for a species in the collection of Mr. Hanley, must be changed should it prove to be a well-defined species. 4. TIVELA DOLABELLA, Sowerby. Cythereea cMabella, Sowerby, Thesaurus Conch, iii. p. 619, pl. 127. f. 15; Reeve, Conch. Icon. xiv. sp. 2. Hab. Mouth of the Macusi River, Quilimane, East Africa. This species was originally described from a specimen in Cum- |