Sea and freshwater molluscs (Bivalvia, 'Acephala')
Lithograph, by Ernst Haeckel, published 1904

1. Cytherea Dione (Pitar dione, Hysteroconcha dione), opening view
2. Cytherea Dione (Pitar dione, Hysteroconcha dione), valve view
3. Cytherea Dione (Pitar dione, Hysteroconcha dione), hinge view
4. Cardium aculeatum (Acanthocardia aculeata), valve from outside
5. Cardium aculeatum (Acanthocardia aculeata), side view
6. Hemicardium cardissa (Corculum cardissa), valve from outside
7. Hemicardium cardissa (Corculum cardissa), opening view
8. Hemicardium cardissa (Corculum cardissa), frontside view
9. Hemicardium cardissa (Corculum cardissa), backside view
10. Tridacna squamosa (Tridacna squamosa), hinge view
11. Tridacna squamosa (Tridacna squamosa), opening view
12. Tridacna squamosa (Tridacna squamosa), valve from outside
13. Tridacna squamosa (Tridacna squamosa), valve from inside
14. Hippopus maculatus (Hippopus hippopus)