Cyrenoida implexa, anatomical drawings. 8. Right view, valve removed, structures seen by transparency of mantle lobe; 9. Mantle border, transverse section in its ventromedial portion; 10. Gill, transverse section in its central portion; 11. Right view, right mantle, and gill removed; 12. Postero-ventral visceral region, ventral view, showing fusion of inner demibranchs in siphonal base and mantle fusion at siphonal area. Scale bars: 2 mm.