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

spect they agree fairly well with C. cruralinica. Distinction-can also be made on the absence of the pedicle collar. On external characters the nearest form seems to be the one described by NOUTSOUBIDSE (1945). The only difference is the suberect umbo. It also resembles "

Te- rebratulina" martiniana, but its ribs are sharper, the anterior margin is more rounded and the brachial valve is more convex. MIDDLE MISS (1976) gave a detailed description of "

Tere- bratulina'

1 martiniana. His form is closely comparable to our in its shape, similar P/A ratio, character and number of ribs and the features of the growth lines. On the other hand, our form is sulcate with sharp ribs and without granular ornamentation on the extreme posterior part of the shell. SCHMID (1971) described 25 juvenile specimens as T. cf. martiniana from the Middle and Upper Albian of the Hannover area. He divided them into two intraspecific groups. Unfortunately, transverse sections have not been made of this material. MIDDLEMISS (1976) remarks that 2 specimens in the Sedgwick Museum are externally similar to SMIRNOVA's (1966) C belbekensis (Hauterivian) and C. rotunda (Lower Aptian). T\_ martiniana is a rare and not well-known species in the Lower Cretaceous of England and northern Germany. Little is known about this group. Further investigation and more material are required for understanding its taxonomy. Cruralina sp. (Plate II: 6-9) /mm/ to I Material: Complete specimen Pedicle valve Fragmentary specimen Szilas-árok 4 6 2 Bocskor-hegy adult 15 19 juvenile 7 2 Közöskuti-árok adult 2 15 1 juvenile 1 Dimensions (mm ) L 12. 7 W 8. 3 T 5 15 11. 6 6. 3 For further data, see Fig. 9. 0 » 10 15 Fig. 9 Scatter diagram of the relationship of width to lenth in Cruralina sp. Kay to the scatter diagrams: â Szilas-árok o Eperkés-hegy • Közöskuti-árok o Bocskor-hegy Description: The biconvex shell is elongated oval in outline with a rounded anterior part. In the anterior third of the brachial valve a low, wide sulcus develops. P/A ratio is 2: 1 Maximum thickness is at the mid-line. The pedicle valve is more convex than the brachial one. Maximum convexity is at the posterior third. The umbo is straight and elongated; as it is broken, accurate description can not be given. The lateral comissure is gently arched, the anterior one is broadly and slightly sulcate (Fig. 10). The costae are low and narrow, well-marked. Their number is increasing towards the anterior margin usually by intercalation and, in the posterior part, also by bifurcation. About 60 costae can be found at the anterior margin. Fig. 10 Cruralina sp. in anterior view