| OCR Text |
Show 124 DR. GWYN JEFFREYS ON THE MOLLUSCA OF THE [Feb. 19, variety, as well as a specimen from Corsica, are more or less smooth, and sometimes destitute of the spiral striae. Fossil. Pliocene: Red and Coralline Crag, and Monte Mario. Post-tertiary : Norway and Sweden, Scotch and Irish " glacial " beds, Mammalian Crag, Selsea and Leghorn ; 0-460 ft. Among the synonyms are R. minutissima of Michaud and R. multilineata of Stimpson. Not R. striata of Quoy and Gaimard. It is a favourite food of the Eider Duck and other sea-fowl. 32. RISSOA AFFINIS1, Jeffreys. (Plate IX. fig. 8.) S H E L L oblong, slender, rather thin, semitransparent, and glossy : sculpture slight and indistinct, not sharp and thread-like, spiral striae, of which there are about 15 on the last whorl, less than half that number on the penultimate whorl, and mere traces on the next; the topmost whorl is smooth: colour whitish : spire rather elongated : whorls 4, moderately convex, the last exceeding two thirds of the whole ; apex bulbous and somewhat truncated : suture slight: mouth triangular, sharply pointed above : outer lip thin, somewhat expanded : inner lip reflected on the pillar, and thickened: peristome continuous. L. 0*0125. B. 0*005. 'Porcupine' Exp. 1870: Atl. St. Vigo B., 16. A single specimen from each station. Differs from R. striata in being broader proportionately to the length, having 4 instead of 5 or 6 whorls, fewer and less distinct spiral striae, and no trace of longitudinal striae, with an expanded mouth and an acute-angled corner at the top. R. arenaria has a shorter spire, stronger and sharper sculpture, swollen whorls, a deep suture, and roundish mouth. The present species is not R. affinis of Beuoit, which is (ex visu typi) Hydi-obia ventrosa. 33. RISSOA ARENARIA, Mighels and Adams. Cingula arenaria, Migh. & Ad. in Boston Journ. Nat. Hist. iv. (1842), p. 49, pi. iv. f. 24. ' Lightning ' Exp. St. 2. Distribution. Spitzbergen, Vadsd (Verkruzen) ; Bohuslan (Loven), Greenland, Canada, Casco B., and Grand Manan ; 5-40 fms. Fossil. Post-tertiary : Greenock and Canada. R. mighelsi of Stimpson, who changed the name, because he said this species was not the Turbo arenarius of Montagu. But Montagu never described or mentioned any species of that name. Helix arenaria of Maton and Rackett (1'urbo arenarius of Turton) is Odostomia decussata. R. exarata of Stimpson is a variety of the present species, judging from his description and figure, as well as from a typical specimen given me by the lamented Professor; this variety was also found by Professor G. O. Sars in Fin mark. The animal was described bv me in the ' Annals and Magazine of Natural History ' for March 1877. 1 Allied, sc. to B. striata. |
