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Show 1890.] MARINE MOLLUSCA OF ST. HELENA. 277 ultimo circiter 22, inferne obsoletis) sulcisque duobus transversis, circa partem inferiorem, instructi; apex parvus, globosus, involutus; apertura irregulariter ovata, basi sub-effusa ; columella vix torta, leviter reflexa. Longit. 3 millim., diam. fere 1 ; apertura 1 longa, \ lata. Besides the two spiral sulci which encircle the lower part of the whorls between the riblets, some microscopic spiral striae are observable at the upper part, and also upon the base of the body-whorl. The little glassy nucleus is uncoiled and at a right angle to the axis of the shell. CINGULINA CIRCINATA, A. Adams. Cingulina circinata, A. Adams, Ann. & Mag. Nat. Hist. 1860, vol. vi. p. 414 ; Angas, Proc. Zool. Soc. 1867, p. 201. Hab. North China, Japan, and Port Jackson. Several small specimens of this species were obtained at St. Helena. After a very careful examination under a microscope, I cannot detect any difference whereby they can be distinguished from this eastern form. The sculpture consists of three subequal spiral ridges on each whorl, and a very fine thread borders the suture. The nucleus is convex and sinistral, as in Mathilda, which I regard as a subgenus of Cingulina. The finest specimen from Japan wbicb has been examined is 12 millim. in length, and consists of thirteen normal whorls, whilst the largest St. Helena example is only 5 millim. long and has eight volutions; but had this shell been permitted to go on growing, it would, by the addition of 5 more whorls, have attained a length fully as great as the Japanese example. CINGULINA (MATHILDA) QUADRICARINATA (Brocchi). Hab. Mediterranean, Bay of Biscay, Madeira. The distribution and references of this beautiful species are given by Jeffreys in his report on the Mollusca of the ' Porcupine' Expedition (Proc. Zool. Soc. 1884, p. 364). He observes that the sculpture " varies considerably, and this has, of course, given rise to several synonyms, including Eglisia macandrece of A. Adams." This latter species was described by H. (not A.) Adams l and has six spiral lirae and more numerous and more delicate longitudinal raised lines of growth. Until further specimens are obtained which may connect the two forms I prefer to keep them separate. The three specimens from St. Helena are small, the largest measuring 131- millim. in length. They appear to be a trifle more slender than the ' Porcupine ' specimens and that figured by Kobelt (Jahrbiich. deutsch. Mai. Gesell. 1874, pi. xi. figs. 2, 2 a). The sculpture, however, is precisely similar. The question has been raised by Mr. Watson (' Challenger' Gasteropoda, p. 499), whether the genus Mathilda is the same as Cingulina of Adams ; but I cannot adopt the conclusion at which he arrives namely, " either to suppress Cingulina altogether, or to retain it 1 Proc. Zool. Soc. 1865, p. 753. |