FIGURE 4. Hokkaidoconcha novacula n in New and little known mollusks from ancient chemosynthetic environments

FIGURE 4. Hokkaidoconcha novacula n. sp. from Oxfordian (Late Jurassic) seep carbonates at Beauvoisin, southeastern France; all figured specimens are rubber casts. A. Holotype showing the aperture (FSL 286 452), B. Paratype with slightly rounded (weathered) ribs (FSL 286 453). C. Paratype showing the sharp-crested axial ribs (FSL 286 454). D. Paratype showing spiral cords on the base and the reflected inner lip of the aperture (FSL 286 455).