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Show 1883.] MR. G, B. SOWERBY ON NEW SPECIES OF SHELLS. 31 rather thin, inequilateral, umbones posterior ; both valves faintly irregularly wrinkled with concentric striae; dorsal margin posteriorly sloping to an angle; anterior side arched, and obliquely sloping towards the ventral margin; posterior obliquely truncated; ventral margin very slightly arched; umbonal ridge obtusely angulate ; hinge with cartilage-processes rather small. Long. 35, alt. 26, lat. 13 mill. Hab. Port Jackson (Brazier). Another interesting species of the genus Thracia from the same locality as the one described by Mr. Angus in the 'Proceedings' of 1869, and discovered by the same persevering and intelligent collector. TELLINA BRAZIERI, sp. n. (Plate VIL fig. 2.) Shell transversely ovate, nearly equilateral, moderately thin, dull yellowish white, without markings; concentrically laminated, laminae very fine and thread-like ; umbones acute, rather prominent, approximate ; anterior side rounded, posterior truncated; anterior dorsal margin incurved, posterior sloping in a straight line to form an angle with the side; ventral margin arcuate ; dorsal area slightly depressed; ligament long and narrow. Long. 8, alt. 7, lat. 2 mill. Hab. Port Jackson (Brazier). A remarkable little species having the form and external appearance of an Amphidesma. TELLINA MODESTA, sp. n. (Plate VII. fig. 1.) Shell transversely ovate, rather inequilateral, compressed, thin, white, shining; concentrically very finely striated; anterior side rounded, posterior slightly flexuous ; dorsal margins sloping; ventral margin strongly arcuate; umbones small, approximate; dorsal area very slightly impressed; ligament moderate. Long. 12, alt. 9, lat. 3 mill. Hab. Port Jackson (Brazier). A delicate shining white shell of very simple character. PECTUNCULUS ROBUSTUS, sp. n. (Plate VII. fig. 4.) Shell suborbicular, solid, subequilateral, very pale yellowish brown, here and there sparingly banded and spotted with darker brown ; anterior side rounded, posterior angulated, slightly incurved and depressed above the angle; dorsal margin straight; ligamentary area narrow; umbones rather acute; valves radiately ribbed (ribs prominent, rounded, close-set, about 23 in number, much narrower above the angle), concentrically striated; striae thread-like, crossing ribs and interstices. Long. 40, alt. 37, lat. 22 mill. Hab. ? A very distinct and characteristic species. |
