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Show 1871.] MR. T. DAVIDSON ON JAPANESE BRACHIOPODA. 307 rounded at the front, but when full-grown is nearly straight, or even sometimes slightly sinuated at the frontal margin. The different variations I have observed in this shell are figured in Plate X X X . The foramen is small, and with age becomes gradually more distant from the hinge-line by the development of the deltidium plates. The surface is smooth. In colour it varies considerably : some specimens are ashy white ; others have a general salmon-colour, which deepens into orange-red near the lines of growth or margins of the shell. In some examples, besides a general reddish tint, a few ruddy rays mark the lateral portions of the shell, but rarely so strongly defined as in Sowerby's figure, in which the coloration is exaggerated. Hab. Sowerby states that his specimen of T. rubella was obtained from Japan. Mr. A. Adams dredged it from a clear stony bottom off the pretty little island of Kuro-Sima, at a depth of 35 fathoms. Prof. R. Plumpelly gives as its habitat the wharf at Yokohama, Japan (Ball). Subgenus M A G A S E L L A , Dall. This subgenus would comprise the following recent species :-M. evansi, Dav. ; M. crenulato, Sow.; M. inconspicua, Sow. (according to Dall) ; M. flexuosa. King ; M. (Ter.) suffusa, Reeve (of this species I possess the original specimen, and can assert that it possesses the elevated septum and loop of Magasella) ; M. Icevis, Dall; M. (T.) Cumingii, Dav. ?; and the following two new Japanese species :- MAGASELLA ADAMSI, Dav. (Plate XXX. figs. 23, 24.) Shell small, nearly circular, as broad as long ; dorsal valve slightly convex, and marked with about eleven more or less prominent ribs, of which the central one, in the dorsal valve, is both the largest and most elevated. Ventral valve deeper than the opposite one, with about twelve ribs, of which the two central ones are both the largest and most prominent, leaving a deepish median sulcus between them ; beak truncated by a rather large incomplete foramen; deltidium-plates small; shell-punctures large and prominent; colour white. In the interior of the dorsal valve there exists a Magasella-shaved prominent septum, extending from under the umbonal beak to about half the length of the valve, and to the lateral sides of it are attached the principal pair of lamellae prior to becoming reflected. Length 2, width 2, depth 1 line. Hab. Two examples of this small species were dredged by Mr. A. Adams in 26 fathoms water in the sea of Japan, off the island of Kuro-puna. In some specimens the ribs are almost obsolete. MAGASELLA GOULDI, Dall, MS. (Plate XXXI. fig. 11, a, b, c.) Shell small, transversely oval, wider than long; hinge-line nearly as long as the breadth of the shell; beak somewhat produced and slightly incurved, with a large incomplete horseshoe-shaped foramen ; deltidium-plates very small and widely separated ; false area flattened. Ventral valve deep ; dorsal valve slightly convex. Surface of each |