i6o 



THE HISTORY OF CEEATION. 



SYSTEMATIC SURVEY 



0/ the 4 Classes, 8 Stth-classes, and 21 Orders of Molluscs. 



Classes of 

 Molluscs. 



Svb-classes of 

 Molluscs. 



Orders qf 

 Molluscs. 



Systematic Name 

 qfthe Orders. 



I. Molluscs without head or teeth : Acephala or Anodontoda. 



Spirobranchia 

 or 

 Brachiopoda 



I. Eoardines 



Hinge-less 



II. Testicardines 

 Hinge-less 



1. Stalked 



2. Flattened 



3. Fleshy armed 



4. Calcareous-armed 



1. Lingulida 



2. Cranlada 



3. Sarcobracliia 



4. Sclerobrachia 



II. 



iHusscIs 



or 



?3[atr=gills 

 Lamellibranchia 



or 

 Phyllobranchia | 



III. Asiphonia 

 Mussels without re- 

 spiratory tubes 



5. One-muscled 5. Monomya 



6. Uneven-muscled 6. Heteromya 



7. Even-muscled 7. Isomya 



IV. Siphonida ( 8. Round-mantled 8. Integripalliata 

 Mussels with respi- \ 9. Bay-mantled 9. Sinupalliata 



ratorij tubes (lO- Tube-mussels 10. luclusa 



II. Molluscs with head and teeth: Cephalophora or Odontophora. 



III. 



Snails 



Cocblides 



or 



Gasteropoda 



V. stump-headed 

 Perocephala 



VI. Large-headed 



Delucephala 



IS: 



11. Tube-snails 

 Butterfly-snails 



' 13. With hind gills 

 1 14. With fore gills 

 15. Swimming-snails 

 1 16. Beetle-snails 

 J 17. Snails with lungs 



11. Scaphopoda 



12. Pteropoda 



13. Opisthobranchia 



14. Prosobranchia 



15. Heteropoda 

 10. Chitonoida 

 17. Pulmonata 



IV. 



Cutties 



or 



^oulps 

 Cephalopoda 



VII. Chamber-Poulps (\8. Pearl boats 

 with four gills \ 19. Ammon's horns 

 TetrahrancUia 



VIII. Ink-Poulps with /20. Ten-armed 

 two gills -! 



Diiranchia (.21. Eight-armed 



18. Nautilida 



19. Ammonitida 



20. Decabrachiones 



21. Octobrachiones 



