Alvania (Alvania) oceani ( d'Orbigny, 1852 )

TĂMAȘ A., TĂMAȘ D. M. & POPA M. V., 2013, Badenian Small Gastropods From Lăpugiu De Sus (Făget Basin, Romania). Rissoidae Family, Acta Palaeontologica Romaniae 9 (1), pp. 57-66 : 60

Alvania (Alvania) oceani ( d'Orbigny, 1852)

Fig. 2d

1852 Rissoa oceani d’Orb. - d’Orbigny, p. 29, nr. 368 1954 Alvania oceani d'Orb. - Friedberg, p. 377, pl. 22, fig. 13

1975 Alvania (Alvania) oceani (d'Orbigny) - Bałuk, p. 82, pl. 9, fig. 17

1981 Alvania oceani d'Orbigny - Krach, p. 49, pl. 15, fig. 1

2004 Alvania (Alvania) oceani (d'Orbigny) - Kowalke and Harzhauser, p. 120, fig. 7A.

Material: two specimens, one from L5 and one from Lp2 (one specimen PMBBU 23859 )

Description: Elongated conical shell with five whorls; up to 2.7 mm in height and 1.40 mm in width. The protoconch is only partly preserved, as more than 2 convex whorls. Ornamentation is not visible under the stereomicroscope. Teleoconch with flattened first whorls and a last convex whorl with canaliculate suture. Ornamentation consisting of rounded axial ribs intersected by finer spiral threads; the latter become more pronounced towards the base of the shell. The last whorl represents about 65% of the total shell height. It is ornamented with 21 axial ribs intersected by 8 spiral threads. The shell base is covered by 5 spiral threads. Drop-like aperture, with inner lip covering the umbilicus and external lip showing inner denticles. Varices are present on the last-but-one whorl and in the aperture area. Distribution: identified in Austria ( Kowalke and Harzhauser, 2004), Poland ( Friedberg, 1954; Bałuk, 1975; Krach, 1981).

Figures

Fig. 2 - a Rissoa acuticosta (Sacco, 1895). b Rissoa clotho Hörnes, 1856. c Rissoa costeiensis Kowalke & Harzhauser, 2004. d Alvania (Alvania) oceani (d'Orbigny, 1852). e Alvania (Alvania) productilis Boettger, 1906. f Alvania (Alvania) perregularis (Sacco, 1895). g Alvania (Alvania) ampulla (Eichwald, 1853). h Alvania (Alvania) helenae Boettger, 1901. i Alvania (Alvania) transiens (Sacco, 1895).