OCR Text |
Show 1877.] ANTHOBRANCHIATE NUDIBRANCHIATE MOLLUSCA. 261 raised openings. Branchiae numerous, small, ramose, non-retractile, arranged in 8 bundles at some distance around the thickened, gently protuberant anus. Oral tentacles moderately large, fleshy, flattened, subcordate in outline, with the border multilobulate. Foot broadly rounded and indistinctly grooved in front, narrower and rounded behind. Colour of the fresh spirit specimen purplish red, mottled with white upon the back, and especially on the sides ; at the commencement of the mantle-expansion along each side are about 12 irregular, subrhomboid, white blotches ; with the exception of a distinct band of transparent purplish white at the extreme border, the remainder of the expansion is red with darker radiating streaks. The rhinophores are red ; the branchiae white, streaked with red ; and the anus is yellow. Underneath, the surface is chiefly mottled with red and white; the sole of the foot is uniform reddish with a yellowish edge; and the margin of the mantle is purplish white. Length (in spirit) 72 millims., extreme breadth 75. Hab. Mauritius. No spicules could be found in the mantle. HEXABRANCHUS ANEITEUMENSIS, sp. nov. H. aneitensis, Bergh [in sched.]. Body oblong-ovate, soft, smooth, depressed. Mantle expanded, especially at the sides and behind, with the edge membranous and fimbriate. Rhinophores with the upper part short, thick, conical, laminated, and recurved ; the pedicels slender; retractile in smoothly marginated cavities. Branchiae short, soft, ramose, in 7 irregular bundles at some distance around the wide anus, the opening of which is slightly raised. Oral tentacles flat, fleshy, with deeply and many-lobed border. Foot from one third to one half the breadth of the mantle, transversely grooved in front, the lateral and posterior borders much flattened. Colour of the spirit specimens, above, mottled red and white, the branchiae streaked with red ; below, the sides and mantle covered with reticulating spotted red markings ; the sole of the foot uniform reddish. Hab. New Hebrides (Aneiteum). HEXABRANCHUS MAURITIENSIS, sp. nov. Form elliptic, moderately depressed, smooth. Mantle expanded at the sides, with the border thinning out, subcrenulate and fimbriate, except in front, where it is rather thickened, and very little of it is free. Rhinophores with the upper portion diagonally laminate, conical, rather slender, pointed, and directed backwards; their cavities with short, plain, sheathing margins. Branchiae in 7 or 8 non-retractile bundles, each containing three or more irregular, short, tripinnate plumes, set round at some distance from the anus. Mouth large ; oral tentacles moderate, fleshy, leaf-like lobes, with crenulate edges. Foot long, truncated in front, extending behind nearly as far as the end of the mantle. |