Kaszab Zoltán (szerk.): A Magyar Természettudományi Múzeum évkönyve 74. (Budapest 1982)

Szabó, J.: Lower and Middle Jurassic Gastropods from the Bakony Mountains (Hungary). Part IV.: Neritacea, Craspedostomatacea, Amberleyacea (Archaeogastropoda)

Remarks : Similar forms are known in wide distribution, but only a few species can be placed with certainty in this genus : DUBAR' S species Purpurinidael and

11 Crossostoma''' atlantis DUB., 1948, Crossostoma cristallinum CARAPEZZA & TAGLIARI, 1894 (FUCINI, 1913), besides the type species. Owing to insufficient knowledge the others are ranged questionably into this genus needing further investigations: Trochus (Ziziphinus) achiardii GEMM.,

G.G., 1878, BOURROUILH'S Crossostoma angulatum GEMM. (1966) and HUDLESTON'S "Trochus spathica" and " Trochus" attrochus. The species "Crossostoma" atlantis DUB. has a peristome like that of a true Crossostoma. This similarity may originate from the adaptation into similar, certainly shallow water habit. Owing to this, comparable thickened peristomes develope in a high number of different groups, in which this character has a systematic value on species level only (for example: Discohelix, Eucyclus). This morphological agreement is regarded as homoeomorphism betwen Boeckhia gen.n. and Crossostoma MORRIS & LYCETT, 1851. The similarly shaped Pterocheilos MOORE, 1867 is differing by its basal projection and the absence of an ornament. DUBAR (1948) has considered, that his species "PurpurinidaeV was comparable with Chartronella species, in accordance with the present writer' s judgement. Boeckhia gen.n. belonging to the family Paraturbinidae, shows a peristomial building similar to that of ChartronellaCossMANK, 1902, and the shape of the two genera are also somewhat similar. However, on the basis of the number of carinae, they are easily distinguishable. Other genera of this family significantly differ both in shape and ornament from Boeckhia gen. n. Boeckhia boeckhi sp. n. (Plate II : figs. 9—10) Holotype : Plate II: figs. 9-10; Locus typicus : Bakonybél, Somhegy; Stratum t y p i c u m : Bajocian submarine horizontal fissure-filling limestone. Derivatio nominis: see above in the name of the genus. Diagnosis : rather sublenticular; peristome higher than half of total height; low axial ridge in the middle of columellar lip; a pseudoumbilicus is present Measurements: H HL HA D W A Plate II: figs. 9-10 9 6.5 11.5 6.5 89° Material: A single, damaged specimen. Shape : Dextral, low conical spire with a whorl-surface being slightly concave above and below the suture and convex medialy. Below the carinate periphery, there is the strongly convex base with a pseudoumbilicus. Outer lip more prosocline than thickened inner one. On the widened part of the latter, a low ridge is present between two shallow furrows. Ornament : Distinct longitudinal lineation and prosocline growth-lines forming a small sinus at the peripherial carina. Distribution : Bakony Mts., Somhegy : Humphriesianum Zone. Remarks : Boeckhia boeckhi gen. & sp. n. has a lower spire than any of the above mentioned species of the genus, and the form of the inner lip is also unique. Family Amberleyidae WENZ, 1938 Genus AMBERLEYA MORRIS & LYCETT, 1851 Amberleya (Eucyclus) alpina (STOLICZKA, 1861) (Plate II: figs. 11-13) 1861 : Eucyclus alpinus STOL. — 1874: Eucyclus alpinus STOL. — 1911 : Eucyclus alpinus STOL. — STOLICZKA, p. 176, pl. II, fig. 12. GEMMELLARO, G. G., p. 98, pl. XII, fig. 13. GEMMELLARO, M., p. 223, pl. X, figs. 26-28., 31.