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Show 1890.] MARINE MOLLUSCA OF ST. HELENA. 297 CYLICHNA CYLINDRACEA (Pennant). Hab. This species occurs throughout " the whole north-east Atlantic, from the Lofotens to the Mediterranean, at the Canaries and Mogador " ( Watson). It was also obtained by the ' Challenger ' at Ascension Island and Tristan da Cunha, and the British Museum possesses specimens collected at Whydah on the west coast of Africa. Several of the specimens belong to the variety "linearis " (Jeffreys, Brit. Conch, vol. iv. p. 416). CYLICHNA ATLANTICA. (Plate XXIV. fig. 10.) Testa ovato-cylindiacea, tenuis, pellucido-alba, nitens, ad verticem anguste perforata, transversim (prasertim supra et infra) tenuissime striata; apertura superne anguslissima, antice leviter dilatata; labrum tenue, supra verticem anfr. ultimi productum; margo columellaris callo tenui reflexo indutus, inferne obsolete subtruncatum. Longit. 5| millim., diam. 2\. This species has more curved outlines than C. cglindracea, has a perforate apex, and an umbilical chink. The thin columellar callosity extends up the whorl, and joins the upper extremity of the outer lip. CYLICHNA BIDENTATA (d'Orbigny.) Bulla bidentata, d'Orbigny, Sagra's Hist. Cuba, Moll. vol. i. p. 125, pi. 4. figs. 13-16. Hab. West Indies. The specimens from St. Helena agree in all respects with this species, except that the lower columellar tooth, orfold, is less developed. Similar variation occasionally occurs in West-Indian examples. TORNATINA RECTA (d'Orbigny). Bulla recta, d'Orbigny, Sagra's Hist. Cuba, vol. i. p. 131, pi. 4 bis. figs. 17-20. Hab. West Indies. A single specimen is all I have seen from St. Helena. It has the spire rather less elevated than d'Orbigny's type. PHILINE QUADRATA, Searles Wood. Hab. North Britain, Norway, Greenland, Massachusetts Bay, Azores. A single specimen was dredged in 50-80 fathoms. It has the transverse sculpture rather finer than usual. HAMINEA HYDATIS (Linne). Hab. British Coast, Mediterranean, &c. None of the specimens from St. Helena exceed 10 millim. in length ; they therefore are probably not full-grown. |