Fig. 7. A. Paraparchites calculus (Glebovskaja and Zaspelova in Zaspelova, 1959). Tecnomorph right valve PIN 5128/1; MDF, Porkhov section, sample 6/4; Porkhov Beds, Palmatolepis punctata Zone. B. Palaeocopina gen. et sp. indet. Carapace PIN 5128/2 in left lateral view; MDF, Izborsk Quarry section, sample 5/3; Dubnik Beds, Pa. transitans Zone. C. Gravia? sp. nov. aff. schallreuteri Becker, 1970. Carapace PIN 5128/3 in left lateral view; CDF−9/9; Semiluki Horizon, Pa. punctata Zone. D. Buregia sp. Carapace PIN 5128/4 in left lateral view; CDF, Il'men borehole, sample 830; Semiluki Horizon, Pa. punctata Zone. E. Buregia aff. depressa Polenova, 1953. Carapace PIN 5128/5 in left lateral view; MDF, Izborsk Quarry section, sample 5158−O2; Chudovo Beds, Pa. transitans Zone. F. Buregia sp. nov. Carapace PIN 5128/6 in left lateral view; CDF, Il'men borehole, sample 849; Semiluki Horizon, Pa. punctata Zone. G. Subtella cf. deca Zaspelova 1952. Left valve PIN 5128/7; MDF, borehole No 5, sample i5/207; Pa. punctata Zone. H. Pseudonodella cf. nodosa Zaspelova 1952. Right valve PIN 5128/8; MDF, Izborsk Quarry section, sample 5/4; Dubnik Beds, Early Frasnian. I. Nodella aff. tichonovichi Zaspelova, 1952. Male? left valve PIN 5128/9; MDF, borehole No 6, sample 6/44; Porkhov Beds, Pa. punctata Zone. J–L. Nodella aff. dobroljubovi Schishkinskaja, 1968. J. Right female valve PIN 5128/10; CDF, Il'men borehole, sample 58; Sargaevo Horizon, Pa. transitans Zone. K. Male right valve PIN 5128/11; MDF, Izborsk Quarry section, sample 5/1; Dubnik Beds, Pa. transitans Zone. L. Female left valve PIN 5128/12; MDF, Izborsk Quarry section, sample 5/1; Dubnik Beds, Pa. transitans Zone. M–O. Nodella conotuberculata Zaspelova, 1952. M. Female left valve PIN 5128/13. N. Male left valve PIN 5128/14. O. Male right valve PIN 5128/15. MDF, Porkhov section, sample 5157/2; Porkhov Beds, Pa. punctata Zone. Scale bars 0.1 mm, except B for which is 0.2 mm.