32(j ESSAY ON CLASSIFICATION. 



CL. PISCES. Orel. Dermopteri, Malacopteri, Pharyngognathi, Anacan- 

 thini, Acanthopteri, Plectognathi, Lophobranchii, Ganoidei, Pro- 

 topteri, Holocephali, Plagiostomi. 

 Province. ARTICULATA. Hornogangliata. (Owen.) 



CL. ARACHNIDA. Ord. Derinophysa, Trachearia, Pulinotrachearia, and 



Pulmonaria. 



CL. INSECTA. Sub-class: MTRIAPODA. Ord. Chilognatha and Chilo- 

 poda. Sub-class: HEXAPODA. Ord. Aptera, Diptera, Lepido- 

 ptera, Hymenoptera, Homoptera, Strepsiptera, Neuroptera, Or- 

 thoptera, and Coleoptera. 



CL. CRUSTACEA. Sub-class : ENTOMOSTRACA. Ord. Trilobites, Xipho- 

 sura, Phyllopoda, Cladocera, Ostracopoda, Copepoda. Sub-class: 

 MALACOSTRACA. 1. Edriophthalma. Ord. Lsemodipoda, Iso- 

 poda, Amphipoda. 2. Podophthalma. Ord. Stomapoda, De- 

 capoda. 



CL. EPIZOA. Ord. Cephaluna, Brachiuna, and Onchuna. 

 CL. ANNELLATA. Ord. Suctoria, Terricola, Errantia, Tubicola. 

 CL. CIRRIPEDIA. Ord. Thoracica, Abdominalia, and Apoda. 

 Province. MOLLUSCA. Heterogangliata. (Owen.) 



CL. CEPHALOPODA. Ord. Tetrabranchiata and Dibranchiata. 

 CL. GASTEROPODA. A. MONCECIA : Ord. Apneusta (Roll.), Nudibran- 

 chiata, Inferobranchiata, Tectibranchiata, Pulmonata. B. DKE- 

 CIA. Ord. Nucleobranchiata, Tubulibranchiata, Cyclobranchi- 

 ata, Scutibranchiata, and Pectinibrauchiata. 

 CL. PTEROPODA. Ord. Thecosomata and Gymnosomata. 

 CL. LAMELLIBRANCHIATA. Ord. Monomyaria and Dimyaria. 

 CL. BRACHIOPODA. Only subdivided into families. 

 CL. TUNICATA. Ord. Saccobranchiata and Taeniobranchiata. 

 Sub-province. RADIARIA. 1 



CL. ECHINODERMATA. Ord. Crinoidea, Asteroidea, Echinoidea, Holo- 



thurioidea, and Sipunculoidea. 

 CL. BRYOZOA. Only subdivided into families. 

 CL. ANTHOZOA. Only subdivided into families. 

 CL. ACALEPHJB. Ord. Pulmograda, Ciliograda, and Physograda. 

 CL. HYDROZOA. Only subdivided into families. 

 Sub-province. ENTOZOA. 



CL. CCELELMINTHA. Ord. Gordiacea, Nematoidea, and Onchophora. 

 CL. STERELMINTHA. Ord. Tamioidea, Trematoda, Acanthocephala. 



Turbellaria. 

 Sub-province. INFUSORIA. 



CL. ROTIFERA. Only subdivided into families. 



CL. POLYGASTRIA. Ord. Astoma, Stoinatoda. Rhizopoda. 



1 In the first edition of the work three sub-provinces, Radiaria, Ento- 

 quoted above, published in 1843, the zoa, and Infusoria, are considered as 



