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Show 382 MR. R. B. WATSON ON MADEIRAN MOLLUSKS. [Mar. 18, 10-15 fathoms; Piedade (Canigal), 15-35 fathoms; Ponta de S. Lourengo, 25-45 fathoms ; Porto Santo, up to 50 fathoms ; Porto da Cruz, 50 fathoms; Funchal, up to 50 fathoms. I have no doubt this is the Cingula concinna of Monterosato, whose figure is admirable, and his description, though short, characteristic ; one specimen of his species, kindly sent m e by him, I have also compared. Is the species really distinct from R. semistriata 1 M y impression is that they are the same ; and in this I am fortified by the opinion of Mr. Gwyn Jeffreys. Still the two species are unquestionably distinguishable. R. concinna is smaller, more in steps, when mature thicker, hunchier altogether, lip more thickened internally, pillar thicker, point of it more hunchy, mouth smaller and rounder, lines of growth more distinct, the supersutural striae on upper whorls more distinct, spots of colour more broken. None of these are strongly marked features, but may serve in the mean time to justify our acceptance of the distinction into two species of these forms, the responsibility of the distinction resting with the Marquis. What relation does this species bear to R. callosa, Manzoni ? My belief is that they are probably the same; but neither from his description nor from his figure, nor even from the specimens kindly sent me by Mr. M'Andrew, do I find myself able to arrive at any certainty. If they are the same, Manzoni's name must claim priority. There are at least two very marked varieties of this species, one being much thinner, more in steps, and somewhat more elongated than the other; but the two forms are so perfectly linked by intermediate bonds as to defy distinction. There are also great differences in size. Some thus approach R. depict a, from which they differ, however, in this, that in this species the longitudinal stria? are weaker than in R. depicta, the white of the base round the pillar is smaller and less opaque, the red spots are less brown, but, above all, the embryonic tip shows neither the microscopic striae nor the dark brown stain of that species. The other very small variety resembles R. pulcher rima, but is distinguishable by its whole form and by the spiral striae of the surface. RISSOA DEPICTA, Manzoni. (Plate XXXV. fig. 20.) Cingula maculata, Monterosato. Rissoa punctifera, Watson, M S. Hab. Gorgulho, shore; Machico, 10-15 fathoms; Piedade (Canigal), 15-35 fathoms ; Ponta de §. Lourengo, 25-45 fathoms ; Porto da Cruz, 50 fathoms ; Funchal Bay, 50 fathoms ; Teneriffe (M'Andrew's dredgings, fide Manzoni). Sicily: Palermo, shore ; Trapani, coralligenous sand (fide Monterosato). Baron Schwartz v. Mohrenstern marked this species as " not determined, but seems a variety of R. semistriata, Mont." Mr. Gwyn Jeffreys adopts the same view. It is easily distinguishable by its labial varix and thicker lip, want of any angulation at the lower inner corner of mouth, presence of one furrow on body-whorl much stronger than the others, droop of upper corner of mouth below line of this furrow, the peculiarity of the spiral striations as above |