Szabó János szerk.: Fragmenta Mineralogica Et Palaentologica 20. 2002. (Budapest, 2002)

64 SZABÓ, Remarks — The specimens are conical inner moulds of a species, having four equally spaced carinae on the whorls and six marked cords on the base between the periphery and the edge of an axial basal depression that probably indicates a narrow umbilicus. The Per§ani specimens are similar to Riselloidea noszkyi SZABÓ, 1995, found in the Bakony Mts Sinemurian (Hungary). However, this latter species have also Jcollabral riblets that are also reflected on the inner mould. Another comparable species is the Late Sinemurian to Pliensbachian Riselloidea multistriata (BÖCKH, 1874) but it differs in having much smaller spiral angle, higher volutions and weaker spiral cords of the whorls that are inequally spaced. Specimens of better preservation are needed to a more accurate identification. Subclass Euomphalomorpha BÄNDEL & FRYDA, 1998 Superfamily PCirroidea COSSMANN, 1916 Family PDiscohelicidae SCHRÖDER, 1995 Genus Valamidiscus n. gen. Type species — Valamidiscus persanyensis n. gen. & n. sp. (see below). Name — valami (Hungarian) = (in composed words) some; discus (Greek in Latinised form) = disc. Diagnosis — False sinistral, discoidal shell with deeply concave spire and shallow, almost plane umbilicus. Protoconch slightly raised in deeper excavation, this way indicating spire. Whorls rather loosely coiled, therefore sutures deeply grooved. Shell moderately, but not evenly thick-walled; outer (back) side more thickened. Whorls have two spiral angulations, both bearing one carina. Third spiral carina on strongly arched outer side slightly above periphery. Adapical suture runs just along middle spiral carina, lower (umbilical) suture follows periphery of preceding whorl. Inner space of whorls rounded at apparent peristome. Growth lines marked on juvenile, delicate on last whorl. Their orientation nearly orthocline between spire suture and adapical angulation, feebly opisthocyrt between pairs of carinae, and feebly prosocyrt between lowermost carina and umbilical suture. Valamidiscus persanyensis n. gen. & n. sp. nom. nud. 1915: Discobelix transsylvanicus n. sp. — VADÁSZ, p. 237. Holotype — Plate I: 1-6, 10 Type locality — Tepe Valley (Töpe-patak), Raco§ul de Jos (Alsórákos), Per§ani Mts (Persányi-hegység), Romania. Type strata — Most probably "Adnet" type red, nodular, marly limestone; slight possibility of coming from "Hallstatt" type limestone, which has similar megascopic characters. Type level — Most probably Sinemurian; slight possibility of belonging to the Upper Triassic. Name — Refers to the Per§ani Mts but the spelling follows the Hungarian name as used in the early publications. Diagnosis — See that of Valamidiscus above. Material — A single, slightly damaged, shelly specimen with micritic infilling. Measurements H HL HP D WP AA AL AUA AUL Plate I: 1-6, 10 *6.6 *6.6 *6.6 :;

T9.3 *6 :;- ~ 170 247 210° Description — In the available specimen, the protoconch is poorly preserved Its shape is slighdy trochospiral and dextral, there is a hole ín the central part but it is impossible to see whether the first whorl was open coiled or the initial chamber lacking owing to damage. No peristome part preserved. On naturally etched parts of the shell, two layers with oriented structural elements are observable. This fact suggests that both shell layers must have been originally made of calcite because in the red, nodular limestones of deep water origin, the original aragonitic shells always dissolved, substituted or recrystallyzed into irregular mosaic structure. The outer shell layer consists of fine fibres of calcite normal to the growth-lines. The fibres of the subsequent growth phases on the spire and umbilical whorl sides join to each other in a pattern of spiral arms, starting at the adaxial suture and tending to the abaxial suture. Some of the "spiral arms" are elevated like a thread, suggesting that the periostracum of the shell might have Explanation to Plate I 1-6 Valamidiscus persanyensis n. gen. & n. sp., holotype. —1-4: x4; 5-6: natural size 7 Eucyclus sp. — xl.5. 8 }Prvœmdus scherinus (G.G. GFJvlML^LLARO, 1874). — xl.5. 9 Riselloidea aff. noszkyi SZABÓ, 1995. — x2. 10 Valamidiscus persanyensis n. gen. & n. sp., holotype. — Strongly (xl2) magnified part of the shell surface on the umbilical side to show the "spiral arm" arrangement of the outer calcite fibres.