Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 71. (Budapest 1979)
Szabó, J.: Lower and Middle Jurassic Gastropods from the Bakony Mountains (Hungary). Part I.: Euomphalidae (Archaeogastropoda)
Fig. 4. Measurements and abbreviations used in the descriptions: D = diameter, H = whorl-height, S = peristomal width, A = spiral angle, U = umbilical angle of the two ratios. In the case of D. orbis, the smaller scatter indicates too, that the more realistic values came from the H/D ratio. This can be due to special case of the presence or absence of carinae on the keels. The absence of carinae may reflect in a 0.5 to 2 mm decrease in the H values. In the case of a division with larger numbers (e.g. H/D) this results in lower scatter than in the case of a division with smaller numbers (e.g. H/S). The higher scatter can be related to preservation conditions: damaged shelly and inner entire shelly and outer mould specimens mould specimens (carinae absent) (carinae present) 1.0 ( H/S ( 1.3 1.3 < H/S < 1.5 The ornamentation and the dimensions do not show definite tendency with age. On the basis of the good earlier descriptions and illustrations this species can be easily distinguished. Only its distinction from Discohelix calculiformis DUNKER, 1848, is problematic, because of the poor description and figure of the latter form. Some earlier authors (e.g. HÖRNES 1853, STOLICZKA 1861) united this form with D. orbis. Distribution — Eastern Alps, Hierlatz limestone; Eastern and Western Sicily, "Pygope aspasia zone" (Middle Liassic); Caucasus, Pliensbachian; Bakony Mountains: Kericser, beds with mixed Obtusum to Ibex Zone fauna — Spinatum Zone; Közöskúti-árok, Ibex Zone; Gombáspuszta, Ibex Zone; Lókúti-domb, Davoei-Zone; Kávástető, Davoei Zone; Büdöskútpuszta, Davoei — Spinatum Zone; Középhát, Davoei — Margaritatus Zone; Bocskorhegy, Stokesi Zone; Hamuháza, Ibex Zone. Discohelix cf. ornata (HÖRNES, 1853) (Plate I: fig. 4) cf. 1853: Euomphalus ornatus HÖRNES — in HAUER, p. 760. cf. 1861 : Discohelix orbis REUSS-STOLICZKA, p. 182., pi. 3., fig. 9. cf. 1912: Discohelix orbis REUSS-M. GEMMELLARO, p. 218., pi. 9., figs. 9-12. Measurements: D H S H/D H/S A U Plate I: fig. 4 — 5.1 6 — 0.85 — — Material — Two fragmentary specimens with the visible parts of the characteristically sculptured last whorl and 2 juvenile specimens of probable identity with this form. Shape — The general shape of the shell is very near to that of D. orbis, but the two juvenile specimens refer to a somewhat smaller spiral angle, i.e. in con'radiction to the equally deep two sides of D. orbis, here the spiral side is less concave than the umbilical one. Sculpture — As compared to D. orbis, in this form the transversal ridges of the last whorls and the carinae on the keels are much stronger.
