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Show 1890.] MARINE MOLLUSCA OF ST. HELENA. 269 T. Conry at Ascension, and presented by him to the British Museum, has, however, tubercles as in R. ccelata. The number of the nodules seems to be very variable, and a character of no specific importance. With this species may also be united R. ponderosa, Reeve, the locality of which was unknown to its author, and some shells labelled R. quercina, Mdrch \ in Cuming's collection, said to have come from Guinea, evidently belong to the same species. As I have been unable to consult the work of Schrdter, referred to by Mdrch, who gives no description of his species, I cannot say whether these specimens are correctly identified. They are peculiar in having the nodules on the upper whorls as in typical specimens. RANELLA THOM.E, d'Orbigny. Hab. St. Thomas (d'Orbigny) ; Madeira (Watson) ; Canary Islands (' Challenger') ; Cape Verde Islands (Brit. Mus.) ; Mauritius (Robillard). D'Orbigny's description of this species (Sagra's Hist. Cuba, Moll. vol. ii. p. 164) was based upon an old dead specimen, entirely devoid of colour, now in the British Museum. In fresh examples the aperture is tinted with pale rose, aud the varices and spiral ridges are irregularly spotted and dotted with brown. The enlarged figure in the above-mentioned work (pi. xxiii. fig. 23) is not at all good. The labrum is not so bulging, the granules are not so beadlike, the body-whorl is more constricted below, the varix on the left, and the basal canal is directed to the right and not to the left. The largest specimen in the Museum is from St. Vincent, Cape Verde Islands, and measures 22 millim. in length. This species also occurs at the Mauritius, and has been named R. bergeri2. This distribution supports Tryon's opinion, that R. thomce should be considered to be the same as R. rhodostoma, and indeed, excepting that the brown dotting is more conspicuous and the colour of the aperture different, there is little to found specific distinction upon. I cannot, however, agree with that author in considering R. cruentata and R. rhodostoma forms of one and the same species. NATICA TURTONI. (Plate XXI. figs. 14, 14 a.) Testa globosa, late umbilicata, rufescens, plus minus radiatim strigata, zonis quatuor albis, maculis saturate fusco-rufis, quadratis, inlerruptis, cincta, striis incrementi, ad suturam leviter plicatis, sculpta, epidermide decidua, sublamellata, induta; anfractus 4-5, celeriter accrescentes, convexi, sutura profunda sejuncti, ultimus magnus, aperluram versus leviter expansus vel tubiformis; umbilicus albus, magnus, callo mediocriter tenui medio instructus ; apertura dilatata, semicircularis, intus albida, coloribus externis leviter conspicuis. Diam. maj. 19 millim., min. 14, alt. 18. 1 Cat. Conch. Yoldi, p. 106. 2 Canefri, Mem. Soc. Malac. Belgique, 1880, vol. xv. p. 50, pi. 2. figs. 1, 2. PROC. ZOOL. Soc-1890, No. XIX. 19 |