FIGURE 5. Circunula n in Revision of the Bivalvia from the Upper Jurassic Reuchenette Formation, Northwest Switzerland—Ostreoidea

FIGURE 5. Circunula n. gen. cotyledon (Contejean, 1859). 1–4. Lectotype: 1, idealized drawing of a bivalved specimen, refigured from Contejean (1859, pl. 24, fig. 15), MC 27E-105, Rôce in Montbéliard, Lower Kimmeridgian; 2, anteroventral view of LV attached on a Trichites fragment (refigured from Contejean 1859, pl. 24, fig. 16); 3, external view of RV (with attached paralectotype, revealed during preparation); 4, anteroventral view. 5–6. Paralectotype, small LV (MC 27E-105a), attached on lectotype: 5, interior view; 6, prosodetic ligament area. 7. Paralectotype, RV interior, with opisthodetic ligament area, MC 27E-104, same locality and age as the lectotype. 8–9. Paralectotype, MC 27E-108, Arbouans near Montbéliard, France, Upper Oxfordian; 8, thick-shelled LV, idealized drawing refigured from Contejean (1859, pl. 24, fig. 17); 9, same LV, interior view. Scale bars 5 mm and 10 mm.