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Show 1878.] MR. G. F. ANGAS ON N E W RIVALVE SHELLS. 859 Fig. 6. Syntomis albifrons, n. sp., p. 845. 7. Dreata taooensis, n. sp., p. 848. 8. Syntomis berinda, n. sp., p. 845. 9. Potera marginata, n. sp., p. 852. 10. Pitasila moolaica (f, n. sp., p. 847. 11. Hyperythra angulifascia, n. sp., p. 851. 12. Omiza schistacea j , n. sp., p. 851. 8. Descriptions of six Species of Bivalve Shells in the Collection of Mr. Sylvanus Hanley, F.L.S., and of a Helix from the Solomon Islands. By GEORGE FRENCH ANGAS, C.M.Z.S., F.L.S., &c. [Received September 19, 1878.] (Plate LIV.) SEMELE HANLEYI, 11. sp. (Plate LIV. fig. 1.) Shell transversely ovate, subequilateral, solid, cream-coloured, tinged with violet below the umbones, with narrow irregular descending white rays towards the base, with several zigzag purplish markings near the centre of the valves ; sculptured all over with narrow prominent close-set, somewhat flattened, transverse ridges, which become rather sharp and irregular posteriorly and erectly scabrous at the margin, whilst radiating from the umbones close to the anterior dorsal margin are six close-set ribs, upon which the transverse ridges become nodulous at the points of intersection ; umbones prominent, sharp, approximate ; posterior dorsal margin nearly straight, anterior one very slightly incurved, ventral margin acute ; dorsal area stained with deep purple; valves slightly gaping and flexuous posteriorly; interior of the valves yellow in the middle, stained with rays of violet and rose-colour. Long. 11, alt. 8, lat. 4 lines. Hab. Japanese seas (Belcher). Collection of Hanley. A very charming shell; the sculpture of the anterior portion reminding one of certain species of Psammobia. SEMELE APHRODITE, n. sp. (Plate LIV. fig. 2.) Shell orbicular, nearly equilateral, rather thin, white, with the posterior half of the umbones tipped with rose-colour, from which descend four or five irregular bundles of more or less narrow, faint pink rays, which become a little deeper in colour at the lines of growth and near the base ; concentrically sculptured with narrow, thread-like, somewhat distant lamellae, the spaces between which are crossed with exceedingly fine, close-set, regular hair-like descending striae ; umbones rather tumid, sharp, approximate; dorsal margin posteriorly very slightly arched, anteriorly a little incurved ; dorsal area freckled with a few reddish spots ; ventral margin strongly arcuate. Long. 7, alt. 6, lat. 3 lines. |
