204 ESSAY ON CLASSIFICATION. Part I. 



CLASSIFICATION OF OWEN. 



The following diagram is compiled from K. Owen's Lectures on the Comparative Anatomy and 

 Physiology of the Invertebrate Animals, 2d edit., London, 1855, 1 vol. 8vo. 



Province. Veutebuata. Myelencephala. (Owen.) 



Cl. M a m m a I i a . "] 



Tlie classes Mammalia, Aves, and Rcptilia are not v^t included in the second volume 

 Cl -A. V e s V 



I of the "Lectures," the only one relating to Vertebrata thus far published. 



Cl. Rep t ilia. J 



Cl. Pisces. Ord. Dermopteri, Malacopteri, Pharyngognathi, Anacanthini, Acanthopteri, Plectognathi, 



Lophobranchii, Ganoidei, Protopteri, Holocephali, Plagiostomi. 

 Province. Aktioulata. Homogangliata. (Owen.) 



Cl. Arachnid a. Ord. Dermophysa, Trachearia, Pulmotrachearia, and Pulmonaria. 



Cl. Insecta. Subclass: Myriapoda. Ord. Chilognatha and Chilopoda. Subclass: Hexapoda. 



Ord. Aptera, Diptera, Lepidoptera, Hymenoptera, Homoptera, Strepsiptera, Nevroptera, Orthop- 



tera, and Coleoptera. 

 Cl. Crustacea. Subclass: Entomostraca. Ord. Trilobites, Xiphosura, Phyllopoda, Cladoeera, 



Ostracopoda, Copepoda. Subclass: Malacostraca. 1°. Edriophthalma. Ord. L*modipoda, 



Isopoda, Amphipoda. 2°. Podophthalma. Ord. Stoniapoda, Decapoda. 

 Cl. Epizoa. Ord. Cephaluna, Brachiuna, and Onchuna. 

 Cl. Annellata. Ord. Suetoria, Terricola, Errantia, Tubicola. 

 Cl. C i r r i p e d i a . Ord. Thoracica, Abdominalia, and Apoda. 

 Province. Mollusca. Heterogangliata. (Owen.) 



Cl. Cephalopoda. Ord. Tetrabranchiata and Dibranchiata. 



Cl. Gasteropoda. A. Monoecia: Ord. Apneusta (Koll.), Nudibranchiata, Inferobranchiata, 



Tectibranchiata, Pulmonata. B. D i oe c i a . Ord. Nucleobranchiata, Tubulibranchiata, Cyclo- 



branchiata, Scutibranchiata, and Pectinibrancliiata. 

 Cl. Pteropoda. Ord. Thecosomata and Gymnosomata. 

 Cl. Lamellibranchiata. Ord. Mononiyaria and Dimyaria. 

 Cl. Brachiopoda. Only subdivided into families. 

 Cl. Tunicata. Ord. Saccobranchiata and Tjeniobranchiata. 

 Subprovince. Radiaria.* 



Cl. Echinodermata. Ord. Crinoidea, Asteroidea, Eehinoidea, Holothurioidea, and Sipunculoidea. 

 Cl. Bryozoa. Only subdivided into families. 

 Cl. a n t h o z o a . Only subdivided into families. 

 Cl. a c a 1 e p h a e . Ord. Pidmograda, Ciliograda, and Pliysograda. 

 Cl. Hydrozoa. Only subdivided into families. 

 Subprovince. Entozoa. 



Cl. Coelelmintha. Ord. Gordiacea, Nematoidea, and Onchophora. 

 Cl. S t e re 1 m i n t h a. Ord. Tajnioidea, Trematoda, Acanthocephala. — Turbellaria. 

 Subprovince. Infusoria. 



Cl. Rotifera. Only subdivided into families. 



Cl. Polygastria. Ord. Astoma, Stomatoda. — Rhizopoda. 



1 In the first edition of the work quoted above, published contradistinction of the suhkln<rdoms, MoUusoa, Articulata, 



in 184.'), the three subprovinces, Radiaria, Entozoa, and Infu- and Vertebrata, and that subkingdom is subdivided into two 



soria are considered as one subkingdom called Radiata, in groups, Nematoiieura and Acrita. 



