Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 16. 1993. (Budapest, 1993)
Family Cancellothyrididae Thomson, 1926 Genus Phymatothyris Cooper and Muir-Wood, 1951 Phyniatothyris sp. (Plate I: Fig. 5; text-fig. 18) Material: Szesztra-hegy (1), Alsó-Hajag (1). Dimensions (mm): Specimen M. 93.14. (Text-fig. 18) length: 12.4, width: 10.8, thickness: 8.5. Description - External characters: Small shell, circular in outline. The width is slightly smaller than the length, while the thickness is smaller than half of the length, the angle between the lateral margins is about 100°. Biconvex form, the pedicle valve is significantly more convex than the brachial one. The maximum width and the maximum convexity are situated at half of the length. The beak is small and suberect. The lateral margins are straight, the anterior margin is badly preserved. Both valves are smooth. Internal characters: The internal characters remain unknown, because only one complete specimen of this species was found, so there was no possibility for serial sectioning. Remarks: The small specimen number and the small size render a more precise identification impossible. The external characters of L. ? complanata are slightly similar to this species, however the beak of L. ? complanata is much larger. Text-fig. 18: Drawing of Phymatothyris sp., Szesztra-hesv Suborder TEREBRATELLIDINA Muir-Wood, 1955 Superfamily ZEILLERIA CE A Allan, 1940 Family Zeilleriidae Allan, 1940 Genus Zeilleria Bavle, 1878 Zeilleria mutabilis (Oppel, 1861) (Plate II: Fig. 3; Text-fig. 19) 1992 Zeilleria mutabilis Oppel - Dulai: p. 69, pi. 4, fig. 6, pi. 5, fig. 1. (cum. syn.) Material: Páskom (1), Kávás-hegy (1). Dimensions (mm): Specimen M.93.15. (Text-fig. 19) length: 11.2, width: 10.5, thickness: 6.0. f ) Description - External characters: Small shell, subpenta\ J gonal in outline. The two corners are quite rounded at the lateral margins, while the other two are less rounded at the anO terior margin. The anterior margin is straight. The width is nearly equal to the length, while the thickness is half of the length. The angle between the lateral margins is about 80°. Biconvex form, the convexity of the valves is equal. The maximum width and the maximum convexity are situated at half of the length. The beak is absent. The lateral commissures and the anterior commissure are straight. Both valves are smooth. Text-fig. 19: Drawing of Zeilleria mutabilis. Páskom
