Vörös A. szerk.: Fragmenta Mineralogica Et Palaentologica 14. 1989. (Budapest, 1989)

Order TERE BR A TU LID A Superfamily Terebratulacea Family CANCELLOTHYRIDAE Subfamily Cancellothyrinae Genus Cruralina Smirnova, 1966 Cruralina aff. cruralinica Smirnova, 19 66 (Plate II: 2-5) Material: 3 double-valved specimens, 2 of which are fragmentary, and 1 pedicle valve from the Szilas-árok. 1 complete specimen and 5 pedicle valves from the Bocskor-hegy. Dimensions (mm): L 12. 3 W 9. 7 T 5. 3 Description: The outline of the shell is oval with a triangular posterior part and a rounded anterior one. Maximum width is anterior of the mid-line. The pedicle valve, being much more convex than the brachial one, has its maximum convexity near the umbo. The anterior third of the brachial valve is flat. The umbo is slightly elongated, sub-erect to erect with a small foramen and long, well-marked beak-ridges. The lateral comissure is straight. The anterior margin is slightly arched ventralwards, not folded. The low and narrow costae are well-marked, increasing in number towards the anterior margin usually by intercalation, and also by bifurcation. Their number is about 50 at the anterior margin. There are well-marked growth lines on both valves, increasing in density anteriorly and forming small steps on the shell surface. Internal structures: Pedicle collar is absent. The inner socket ridge is strong, tiongated, bending over the teeth. The teeth are narrow and elongated. Cardinal process is present. The crural bases are aeveloped on their own base, concurrently the inner socket ridges are becoming reduced. The crural processes unite firstly in the ventral side to form the posterior part of the loop, and secondly near the brachial valve to form the anterior part of the loop. The crural processes extend to 2/5 the length of the valve. Muscle scars can not be observed (Fig. 8). Remarks : The a bove described specimen differs from C. cruralinica Smirnova, 1966 in having a suberect umbo and having sparse and more angular ribs. However, two specimens from the Bocskor-hegy have extremely narrow areas separating the ribs, so in this reFig. 8 Transverse sections through Cruralina aff. cruralinica