PRINCIPAL SYSTEMS OF ZOOLOGY 221 



Cl. 5. Pinnifera, or Pisces. 

 Anosteozoaria. 

 Second Type: Entomozoaria. (Articulata.) 



Cl. 6. Hexapoda. (Insecta proprie sic dicta.) 



Cl. 7. Octopoda. (Arachnida.) 



Cl. 8. Decapoda. (Crustacea, Decapoda, and Limulus.) 



Cl. 9. Heteropoda. (Squilla, Entomostraca, and Epizoa.) 



Cl. 10. Tetradecapoda. (Amphipoda and Isopoda.) 



Cl. 11. Myrlapoda. 



Cl. 12. Chaetopoda. (Annelides.) 



Cl. 13. Apoda. (Hirudo, Cestoidea, Ascaris.) 

 Third Type: Malentozoaria. 



Cl. 14. Nematopoda. (Cirripedia.) 



Cl. 15. Polyplaxiphora. (Chiton.) 

 Fourth Type: Malacozoaria. (Molhisca.) 



Cl. 16. Cephalophora. Dioica, (Cephalopoda and Gasteropoda, p. p.) Hermaphrodita 

 and Monoica (Gasteropoda reliqua.) 



Cl. 17. Acephalophora. Palliobranchia (Brachiopoda), LameUibranchia (Acephala), 

 Heterobranchia (Ascidia?.) 



2. Sub-Kingdom. Actinomorpha or Actinozoaria. Form radiate. 

 Cl. 18. Annelidaria, or Gastrophysaria (Sipuncuhis, etc.) 

 Cl. 19. Ceratodermaria. (Echinodermata.) 

 Cl. 20. Arachnodermaria. (Acalephae.) 

 Cl. 21. Zoantharia. (Actinias.) 



Cl. 22. Polypiaria. (Polypi tentacuHs simplicibus), (Anthozoa and Bryozoa.) 

 Cl. 23. Zoophytaria. (Polypi tentaculis compositis), (Halcyonoidea.) 



3. Sub-Kingdom. Heteromorpha or Heterozoaria. Form irregular. 

 Cl. 24. Spongiaria. (Spongiae.) 

 Cl. 25. Monadaria. (Infusoria.) 

 Cl. 26. Dendrolitharia. (CoralHnae.) 



The classification of de Blainville resembles those of Lamarck and 

 Cuvier much more than a diagram of the three would lead us to sup- 

 pose. The first of these systems is founded upon the idea that the ani- 

 mal kingdom forms one graduated series; only that de Blainville in- 

 verts the order of Lamarck, beginning with the highest animals and 

 ending with the lowest. With that idea is blended, to some extent, 

 the view of Cuvier that animals are framed upon different plans of 

 structure but so imperfectly has this view taken hold of de Blainville 

 that, instead of recognizing at the outset these great plans, he allows 

 the external form to be the leading idea upon which his primary 

 divisions are founded, and thus he divides the animal kingdom into 

 three sub-kingdoms: the first, including his Artiozoaria, with a bilat- 

 eral form; the second, his Actinozoaria, with a radiated form, and the 

 third, his Heterozoaria, with an irregular form (the Sponges, Infu- 

 soria, and Corallines). The plan of structure is only introduced as a 



