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Show 32 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Jan. 20, 'Porcupine' Exp. 1870: Atl. St. C. Sagres. A single but living specimen. This prettv species resembles in the coloured bands the well-known N. triseriata of Say; but the whorls are not so ventricose in the present species, the spire is more pointed, and the umbilicus differs in having a small semicircular pad covering more than half of it. The suture in the present species is not excavated as in N. montacuti, and the spire is shorter and also more pointed. It differs from N. macilenta and its probable variety N. rizzce, in shape, consistence, colour, and umbilicus. Professor G. O. Sars has very kindly examined for me the odontophores of the present species and N. triseriata. He finds that the conchological difference of the two species is also well marked in the structure of their respective radulae. "The middle plate is especially different. In N. notabilis the middle tooth is unusually small, and by no means equals the size of the lateral teeth. In N. triseriata the middle plate is rather large and has the middle tooth much larger and more prominent than the lateral teeth. The shape of the plate in each is also different. Moreover the jaws in N. notabilis appear to be much coarser in structure, and the whole radula is also comparatively longer. In both species the inner uncinus exhibits the secondary tooth characteristic of the genus (or subgenus) Lunatia." 8. NATICA SUBPLICATA1, Jeffreys. (Plate IV. figs. 2, 2 a.) S H E L L globular or inclined to oval, rather thick, opaque, and glossy : sculpture, numerous but short and irregular, oblique, longitudinal puckers or wrinkles below the suture of the body-whorl, and the rest of the shell is slightly striated in the same direction: colour ivory-white: spire short, apex pointed : whorls 5, tumid; the last occupies g of the spire in length : suture deepish : mouth triangularly oval, pointed above and rounded below, equal in length to | of the spire : outer lip gently curved and thick-edged: inner lip forming a narrow and nearly even glaze over the whole of the pillar : umbilicus small, ending below in a broadish groove : operculum horny, yellowish. L. 0'4, B. 0-35. 'Porcupine' Exp. 1870 : St. 1, 2, 3, 9, 13, 17a, C. Espichel, 22, 26, 30. Distribution. Bay of Biscav ('Travailleur ' Exp.), off C. Verd I. ('Talisman' Exp.); 370-1192 fms. Differs from other species now described or noticed in respect of the peculiar folds below the suture. 9. NATICA ANGULATA2, Jeffreys. (Plate IV. fig. 3.) S H E L L solid, with a flattened spire and a sharp angular keel on the periphery ; whorls 2-3 ; suture deep ; umbilicus small. L. 0*05, B. 0075. 'Porcupine'Exp. 1869: St. 4. 1870: Atl. 30; Med. 55. All the specimens are very small; but I cannot identify them 1 Plicated underneath the suture. 2 Angular. |