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

ornamentation of this type is unknown in species of similar age; Protorcula KITTL 1894 has another, a suprasutural carina and no suture to suture riblets; Diatrypesis TOMLIN, 1929 bears no spiral ornament. Superfamily Strombacea SWAINSON, 1840 Family Aporrhaidae ADAMS et ADAMS, 1858 Genus PIETTEIA COSSMANN, 1904 Pietteia trispinigera sp. n. (Plate III: figs 12-13) Holotypus : Plate III : fig. 12. — Locus t y p i c u s : Bakonybél, Somhegy. — Stratum typicum: limestone infilling horizontal fissure. — Derivatio nominis : très (Lat.) = three; spine (Lat.) = thorn; gero (Lat.) = bears. Diagnosis: large, bicarinate, dome-shaped embryonal shell; densely-ribbed juvenile whorls, followed by rare parabolic nodes on the angulation up to the penultimate whorl; three protrusion on the slightly expanded outer lip. Measurements: H HL HA D W A Plate III: fig. 12. +30 +16.5+14 18 — 17-12° (+ = smaller than the real values owing to the damage of the specimen) Material — Six, more or less damaged specimens with shell. Shape — The shell is dextral with high spire of slightly cyrtoconoid outline. The whorls are slightly convex with carinate middle part, and are bordered by sutures in moderately deep grooves. On the last whorl, below the periphery (i.e. the carina of the whorls), an other weak break is visible, and both continues into a protruding spine on the peristome. The base is convex on the upper part, and concave near the siphonal canal, without umbilicus. The peristome is markedly expanded, its upper part reaches to the carina of the penultimate whorl. The end of the spine in the continuation of the carina is slightly curved adaperturally and adapically. The lower spine is situated as somewhat arched from the bisector of the angle between the upper spine and the siphonal canal, in the direction of the latter. One unpreparable specimen shows a spine on the carina, ca. 240° before the last peristome. The other shells show only the scar of this element. Ornament — The whole teleoconch is ornamented by fine threads, which appear immediately after the end of the embryonal whorls. In the beginning these cover only the zone between the carina and the lower suture, but after about a half whorl cover the remaining part, too. These occur on the base also with the same density and strength as on the whorls. Some lines are continued upon the peristomal protrusions. The transverse ornament is formed by opisthocyrt growth lines and ribs restricted to the juvenile shell. These latter ones run suture to suture for a length of about one whorl after the end of the protoconch, and are pointed on the carina. They become shorter gradually on the next whorls, resulting in nodes on the carina, rarer than the ribs. Most nodes are parabolic, showPlate III. Figs 1-4. Ochetochilispiceus sp. n.. Somhegy, 1-2 = a paratype, X2.1, 3 = fragmentary protoconch of paratype, X5.7, 4 = holotype J 10138, X2, Figs 5-8. Eucycloidea galaczi sp. n., Somhegy, 5-6 = holotype J 10139. Xl.9, 7 = embryonaljuvenile whorls of holotype, X5.5, 8 = a juvenile specimen showing sculpture, x2.8 Fig. 9. Oonia pennina (PARONA). Kericser, Xl.4 Fig. 10. Pseudomelania! sp., Somhegy, X2.5 Fig. 11. Mathilda (Tricarilda! ) sp., Somhegy, X4.7 Figs 12-13. Pietteia trispinigera sp. n., holotype J 10140, 12 = Xl.9, 13 = embryonal-juvenile part of holotype, X 6 Fig. 14. Maturifusus densicostatus gen. et sp. n., holotype J 10141, X 1.9