Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 14. 1989. (Budapest, 1989)
Distribution: Upper Albian of Cambridge. Orbirhynchia sp. (Plate I: 19-2T)) Material : 6 brachial valves from the Közöskutiárok, 2 brachial and 2 pedicle valves from the Eperkés-hegy. Dimensions (mm): L 17 W 18 11 12 Description: The biconvex shell is pentagonal or triangular, fan-shaped in outline. The brachial valve is inflated, the pedicle one is rather flat, more convex near the umbo. The latter often has a low median sulcus. The umbo is elongated, pointed with conspicuous beak ridges. The valves are ornamented by very coarse, wide, sharp ribs which are only 8 to 10 in number. Remarks : There is no complete specimen in the material, thus the internal structure remained unknown. However, it can be easily separated from Orbirhynchia parkinsoni by external characters: the shell is smaller, its outline is different, the ribs are coarser, wider and less in number. Trichotomy can not be observed in the pedicle valve. Family RHYNCHONE LLIDAE Subfamily Cyclothyridinae Genus Belbekella Moisseev, 1939 Belbekella cf. gibbsiana (Sowerby, 1824) (Plate II: 1) 1872. Rhynchonella gibbsiana Sowerby - PICTET, p. 29, pi. 198, Figs. 1-5 1897. Rhynchonella gibbsiana Sowerby - KARAKASCH, p. 88, pi. 5, Fig. 19 1960. Belbekella gibbsiana Sowerby - SMIRNOVA, p. 383, pi. 5, Fig. 5 1966. Belbekella gibbsiana Sowerby - BOGDANOVA and LOBACHEVA, p. 39, pi. 3, Figs. 5-6 Material : 1 brachial valve from the Bocskor-hegy. Dimensions (mm) : L 11. 3 W 10. 6 Description : The shell is evenly convex, length exceeds width, subcircular in outline with a sharply triangular posterior part and a rounded anterior one. Maximum width is somewhat anteriorly of the mid-line, maximum thickness is at the mid-line. Low, rounded costae develop at the anterior two third of the valve. Their number at the anterior margin is more than 30, the lateral costae are hardly visible. Faint growth lines can be seen on the valve. The lateral comissure is strongly archied (Fig. 7), the anterior one is widely uniplicate, asymmetrical. Remarks : It differs from Belbekella aptiensis (SMIRNOVA, 1972) in having fine, narrow, rounded ribs. The appearance of the growth lines and the fine ribs give it a resemblance to R. gibbsiana figured in PICTET (1872), but our specimen is longer than wide. It agrees closely with the form described by KARAKASCH. Belbekella ci. Fig. 7 gibbsiana in lateral view Sainte-Croix (western Switzerland), England. Distribution : Lower Barremian of Kopet Dag; Barremian and Aptian of Dagestan; Aptian of the northern Caucasus and Georgia.
