Matskási István (szerk.): A Magyar Természettudományi Múzeum évkönyve 79. (Budapest 1987)

Conti, M. A. ; Szabó, J.: Comparison of Bajocian gastropod faunas from the Bakony Mts. (Hungary) and Umbria (Italy)

(A. procera SZABÓ, 1981). Adeorbisina is very similar to Mariottia, the only difference is the possible presence of an umbilicus in the former one. It would be necessary to see the original of Adeorbisina to decide about this problem. If Adeorbisina had an umbilicus really, Mariottia would remain an independent genus in accordance with the principles, mentioned in the general systematic remarks (see above). In the opposite case, it would be a synonym for Adeorbisina. Some of the numerous Bakony and Carpathian species have definite spiral angulation of different length on the last whorl. In the type species this angulation is present only on the expansion of the last whorl but in M. lateumbilicata (UHLIG), for example, the angulation is visible along the whole last whorl. The length of this morphological element is a specific character. Mariottia gibbosa CONTI et FISCHER, 1981 1981 (July): Mariottia gibbosa CONTI et FISCHER, p. 142, Pl. I: figs 11-14. 1981 (December): Adeorbisina procera SZABÓ, p. 63, Pl. II: figs 12-13. 1984: Mariottia gibbosa CONTI et FISCHER — CONTI et FISCHER, p. 143, Pl. III : figs 7a-d, 8a-b. Remarks — Though there are some difference between the spiral angles of the specimens from the two localities, the "gibbosa" and the "procera" names denote the same species. The somewhat smaller spiral angle of the Bakony specimens means only a slight variability of the species. Distribution — Case Canepine, Humphriesianum Zone; Somhegy (Hungary), condensed Subfurcatum to Garantiana Zone. Family Amberleyidae WENZ, 1938 Genus EUCYCLOIDEA HUDLESTON, 1888 Remarks — One of the species assigned to this genus (Eucycloidea galaczi, see below), occurring both in Somhegy and Case Canepine, suggests close evolutionary relationship to Eucyclomphalus. Its shape is very similar: the spire is pagodiform, too, and the umbilicus, uniquely in Eucycloidea, is as broadly open as in Eucyclomphalus. But in E. galaczi, the characteristic Eucycloidea ornament appeared : spiral lines are present between the upper suture and the angulation of the whorls ; marked collabral riblets are visible on the whole shell. The umbilicus is usually narrower in other Eucycloidea species and the anomphalous stage is also imaginable in some uncertain cases. The morphological similarity between Eucycloidea and some amberleyid forms were mentioned by HUDLESTON (1888) as well in the discussion of this genus. Eucycloidea galaczi is regarded as a link in an evolutionary chain near the Eucyclomphalus stage. Owing to this opinion, it is necessary to place Eucycloidea within Amberleyidae. This new systematic position for Eucycloidea may seem too bold because originally it has belonged to a caenogastropod family (Purpurinidae

). The main reason for this previous classification was the presence of a rudimentary siphonal outlet. In the new family, this morphological element is also frequent, its occurrence is one of the reasons why Amberleyidae is in a doubtful ordinal position within A rchaeogastropoda. Eucycloidea galaczi SZABÓ, 1983 1983: Eucycloidea galaczi SZABÓ, p. 42, Pl. Ill: figs 5-8. 1984: Eucyclomphalusgranulatus CONTI et FISCHER, p. 145, fig. 9, Pl. IV: figs la-c. Remarks — The above mentioned names concern the oldest species in this genus. E. galaczi shows the closest relationships with the most likely ancestor of Eucycloidea (see above). All the other species have narrower umbilicus. Distribution — Somhegy, Humphriesianum to Parkinsoni Zone; Case Canepine, Humphriesianum Zone. Family Nododelphinulidae Cox, 1960 Amphitrochus retusus CONTI et FISCHER, 1984 1983: Paraviviana ? sp. — SZABÓ, p. 27, Pl. I: figs 1-3. 1984: Amphitrochus retusus CONTI et FISCHER, p. 146, fig. 10, Pl. Ill: figs 15a-c, 16. Remarks — All the available specimens are fragmentary or juvenile ones but, fortunately, 4 Term. Tud. Múz. Évk. 1987.