Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 75. (Budapest 1983)

Szabó, J.: Lower and Middle Jurassic Gastropods from the Bakony Mountains (Hungary). Part V.: Supplement to Archaeogastropoda; Caenogastropoda

ing by the growth lines clearly. The last ca. one and a half whorl lacks the nodes, but the strength and run of the carina remains uneven. Embryonal shape and ornament — The axis of the protoconch coincides with that of the teleoconch, and is of dome-shape. Only trace of the nucleus is visible on the holotype: it is probably depressed and seems large. This is followed by three embryonal whorls visible by unaided eye, and these are separated from the teleoconch by sharp sculptural boundary. The somewhat convex whorls are smooth except the two tiny suprasutural carinae. only the last quarter-whorl bears gradually strengthening transverse threads. These become strong suddenly at the end of the protoconch. with simultaneous ending of the two tiny carinae, and appearance of the mid-whorl carina characteristic to the teleoconch. Distribution — Bakony. Somhegy: condensed Subfurcatum and Garantiana, and Parkinsoni Zones. Remarks — According to the original description, the build-up of the outer lip in the genus Pietteia is characterzied by a single spine beside the siphonal canal, in the place of the continuation of the periphery. The possession of two spines, recognized in this form, is a feature in the genus Dicroloma GABB, 1868, but this is the only character differing from those of Pietteia. All the other features suggest this latter genus: i. e. the ribbed or tuberculate whorls, contrary the only spirally ornamented Dieroloma shell; the presence of only one, the upper marked carina and the representation of the lower as only a spiral cord in the last whorl of P. trispinigera sp. n., as in the congeneric forms, while the Dicroloma is bicarinate here. Of the contemporary forms, P. /;<7/?»/Í(DESLONGCHAMPS, 1842) is the most similar, but this has only two protrusions on the peristome, and is evenly ribbed up to the penultimate whorl, while P. trispinigera sp. n. is ribbed only in the juvenile shell, then nodose. P. tridactyla (BUVIGNIER, 1843) bears similarly three peristomal protrusions, thus this is most similar in shape, in spite of the fact that these three rostra are markedly shorter. However, its r equal ribbing is a clear distinguishing feature. Superfamily Littorinacea GRAY, 1840 Family Purpurinidae ZITTEL, 1895 Genus EUCYCLOIDEA HUDLESTON, 188S Eucvcloidea galaczi sp. n. (Plate III: figs 5-8) H o 1 o t y p u s : Plate III : figs 5-6. — Locus t y p i c u s : Bakonybél. Somhegy. — Stratum t y p i c u m : limestone infilling horizontal fissure — Derivatio nominis: after A. Galácz (Eötvös Loránd University, Dept. Palaeontology. Budapest), who collected the holotype. Diagnosis : pagodiform juvenile shell, rounded angulation on the last two whorls; slightly convex, widaely-haneromphalous base; somewhat expanded adult peristome; ornament consisting of collabral nd pspiral cords. Measurements: H HL HA D W A Plate III: figs 5-6. 18 9.5 6.5 13 — 52° Material — Eleven, more or less damaged specimens with shell. Shape — The shell is dextral. pagodiform-littoriniform. The whorls are angular, the periphery is carinate. Above the angulation a flat or slightly convex ramp is situated, the surface is convex below. The angulation is accentuated by a carina, and actually only this carina is present on the last whorls of the adult specimens, while the break of the surface is hardly visible. The base is somewhat convex, and curves with a sharp angle into the wide umbilicus. The shape of the peristome is roundedquadrangular, the last peristome of the adult shell is slightly expanded and somewhat thickened. Ornament — The most striking spiral sculptural element is the carina running on the angulation of the whorls. There is an additional spiral cord constantly along the sutures, on the ramp. Some of the specimens show an occurrence of a supracarinal other cord in the whorls of the later growth stages. Between the angulation and the umbilical margin run 8 to 10 additional spiral cords, of these 0 to 3 are visible above the suture, depending on growth stages.