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

The axial ornament consists of weaker and denser cords as compared to those above, and the points of intersections commonly bear tiny tubercles. In some specimens, and on certain parts of the shell, the collabral cords break into tiny ribs, which end in the interspaces of the elements of the neighbouring costella-rows. Thus a characteristic sculpture is resulted on certain parts of the shell. The growth lines are hardly prosocline on the whorls and slightly opisthocyrt on the last whorl, including the base. Embryonal shape and ornament — The apex is blunt, the initial chamber is embraced by the first (planispral) whorl, which is smooth in the beginning, and at its end bears appearing tiny transverse ribs along the upper suture, then, after about 1.5 whorls, the angulation develops in the middle of the whorl. The end of the protoconch can be recorded by this development. Distribution — Bakony, Somhegy : Humphriesianum to Parkinsoni Zones. Remarks —• The most closely allied form of E. galaczi sp. n. is the species Eucycloideagranulata (HÉBERT et DESLONGCHAMPS, 1860), especially of those specimens which have only the subsutural spiral cord on the ramp. However, this new species shows lower whorls, smaller spiral angle, more flattened base and wider umbilicus. These features distinguish the two forms. In other Eucycloidea species the umbilicus is rather narrow, or missing. Genus OCHETOCHILUS COSSMANN. 1899 Ochetochilus piceus sp. n. (Plate III: figs 1-4) Holotypus : Plate III: fig. 4. — Locus t y p i c u s : Bakonybél. Somhegy. — Stratum t y p i c u m : limestone infilling horizontal fissure. — Derivatio nominis : piceus (Lat.) = pitch-black; referring to that most specimens are coated with manganese film. Diagnosis : oval shell-outline with narrow umbilicus; ornament consisting of dense spiral cords and transverse threads. Measurements: H HL HA D W A Plate III: fig. 4. — 14 — 13 — 65-42° Plate III: figs 1-3. 17.5 12 8 11.5 — 71-45° M a t e r i a 1 — Six, more or less damaged specimens with shell. Shape — Dextral shell with oval outline, convex whorls, of which last curves into the similarly convex base without break. The umbilicus is narrow, which is partially (or totally?) covered by the inner lip. The peristome is elongated axially, the outer lip is simple and arched, the inner lip forms a wide. "V"-shaped callus, of which axial wing is reflected and covers the umbilicus. Ornament— The whole shell is covered with spiral cords, which are flattened, lace-like in the last whorl. Between them, random weaker threads also appear. The collabral ornament consists of growth lines, of whichs ome strengthen as the spiral threads, except on the last whorl. These threads, together with the spiral elements, result in cancellate pattern of more or less equal interspaces. The transverse sculptural elements are slightly opisthocyrt and stronger prosocline on the whorls, less on the base. Emryonal shape and ornament— One specimens shows the preserved last whorl of the protoconch (Plate III: fig. 3), which is of convex surface and completely smooth. Its end is marked by sudden appearance of strong, rib-like, opisthocyrt growth lines and spiral lines covering the whorl. Distribution — Bakony, Somhegy : ?Humphriesianum and condensed Subfurcatum and Garantiana Zones. Remarks — The most similar form among the few known species of the genus is the type species, O. subvaricosus COSSMAN, 1899. However, this has anomphalous shell, non-ovate, but rather conical spire-outline with acute apex, and rarer and granulate spiral cords. Furthermore, the here described species lacks the rudimentary varices characterizing the type species. Superfamily Buccinacea LATREILLE, 1825 Family Buccinidae LATREILLE, 1825