196 



ESSAY ON CLASSIFICATION. 



Part I. 



CLASSIFICATION OF LAMARCK. 



Hfetoirc Batnrelle des Anima«K sans vertebres, etc., Paris, 1815-1822, 7 vols. 8vo. - A second edirion with notes has been pul> 

 lished by Messrs. DesHayes and Milne-Edwards, Paris. 1835-184.3, 10 vols. 8vo.-For the successive modifications th.s classi- 

 fication has undergone, see also: Systeme dcs animaux sans vertebres, etc., Paris, 1801, 8vo. -Philosophic zoologique, etc.. Pans, 

 1809, 2 vols. 8vo.-Extrait d« Cours de Zoologic du Museum d'Histoire naturelle, etc., Paris, 1812, 8vo. 



INVERTEBRATA. 



I. Apathetic Animals. 



Cl. 1. Infusoria. Ord. Nuda, Appendiculata. 



Cl. 2. Polypi. Ord, Ciliati (Rotifera), Denudati (Ilydroids), 

 Vaginati (Anthozoa and Bryozoa), and Natantes (Crinoids, 

 and some Halcyonoids.) 



Cl. 3. R a d i a r i a . Ord. Mollia ( Aoalepha;), Echinoderms, (includ- 

 ing Holothuria? and Actinia",) 



Cl. 4. Tunicata. Ord. Bothryllaria (Compound Ascidians), 

 Ascidia, (Simple Ascidians.) 



Cl. 5. Vermes. Ord. Molles and Rigiduli (Intestinal Worms and 

 Gordius), Hispiduli (Nais), Epizoaria; (Epizoa, Lernajans.) 



Do not feel, and move 

 only by their excited irri- 

 tability. No brain, nor 

 elongated medullary mass ; 

 no senses ; forms varied ; 

 rarely articulations. 



II. Sensitive Animals. 



Cl. 6. Insects. (Hexapods.) Ord. Aptera, Diptera, Hemiptera, 

 Lepidoptera, Hymenoptera, Nevroptera, Orthoptera, Cole- 

 opt era. 



Cl. 7. Arachnids. Ord. Antennato-tracheales (Thysanura and 

 Myriapoda), Exantennato-tracheales and Exantennato-bran- 

 chiales (Arachnids proper.) 



Cl. 8. Crustacea. Ord, Heterobranchia (Branchipoda, Isopoda, 

 Amphipoda, Stomapoda) and Homobranchia (Decapoda-) 



Cl. 9. Annelids. Ord. Apoda, Antennata, Sedentaria. 



Cl. 10. C i r r i p e d s . Ord. Sessilia and Pedunculata. 



Cl.11. Conchifera. Ord. Dimyaria, Monomyaria. 



Cl. 12. Mollusks. Ord, Pteropoda, Gasteropoda, Trachelipoda, 

 Cephalopoda, Heteropoda. 

 VERTEBRATA. 



Feel, but obtain from 

 their sensations only per- 

 ceptions of objects, a sort 

 of simple ideas, which they 

 are unable to combine to 

 obtain complex ones. No 

 vertebral column ; a brain 

 and mostly an elongated 

 medullary mass ; some dis- 

 tinct senses ; muscles at- 

 tached under the skin ; 

 form symmetrical, the parts 

 being in pairs. 



III. Intelligent Animals. 

 Cl. 13. Fishes. 

 Cl. 14. Reptiles. 

 Cl. 15. Birds. 

 Cl. 16. Mammalia. 



Feel; acquire preservable ideas; perform with them oper- 

 ations by which they obtain others ; are intelligent in different 

 . degrees. A vertebral column ; a brain and a spinal marrow ; 

 distinct senses; the muscles attached to the internal skeleton; 

 form symmetrical, the parts being in pairs. 



It is not easy to appreciate correctly the system of Lamarck, as it combines 

 abstract conceptions with structural considerations, and an artificial endeavor to 

 arrange all animals in continuous series. The primary subdivision of the animal 

 kingdom into Invertebrata and Vertebrata^ corresponds, as I have stated above, to 



> See, above, Chap. 2, Sect. 1, p. 138. 



