GRADE B  . Metazoa .

Branch a . Parazoa . Phylum' . Porifera (se- SPONGES) . Sub-phylum' . Calcarea . Class . CALCAREA . Orders : Homocoela, Heteracoela . Sub-phylum 2 .

Non-Calcarea . Class I . MYXOSPONGIDA .

Order: Myxospongida . Class 2 . TRIAXONIDA (= HEXACTINELLIDA) . Orders: Amphidiscophora, Hexasterophora . Class 3 . TETRAXONIDA . Sub-Class' . Tetractinellida . Orders: Homosclerophora, Astrophora, Sigmatophora .

Sub-class 2 . Lithistida . No Orders . Sub-class 3 . Monaxonellida . Orders: Astromonaxonellida, Sigmatomonaxonel- lida . Class 4 . EUCERATOSA . Order: Euceratosa . Branch b . Enterozoa . Grade' .

ENTEROCOELA (see

COELENTERA) . Phylum 2 . Hydromedusae or Hydrozoa (q.v.) . Class . HYDROMEDUSAE, (q.v.) . Orders: Eleutheroblastea, Hydroidae seu Leptolinae (Sub-orders: Anthomedusae, Leptomedusae), Hy- drocorallinae, Greptolitoidea Trachylinae (Sub- orders: Trachomedusae, Narcomedusae), Siphono- phora . Phylum 3 . Scyphomedusae (q.v.) . Class . SCYPHOMEDUSAE . Orders: Cubomedusae, Stauromedusae, Coronata, Discophora . Phylum 4 .

Anthozoa (q.v.) . Class . ANTHOZOA . Sub-class I . Alcyonaria . Orders: Stolonifera, Akyonacea, Pseudaxonia, Axifera, Stelechotokea, Coenothecalia . Sub-class 2 . Zoantharia . Orders: Zoanthidea, Cereanthidea, Antipathidea, Actiniidea (Sub-orders: Malacactinias and Scleractiniae or Madreporia) . Phylum 5 . Ctenophora . Class .

CTENOPHORA . Sub-class I . Tentaculata . Orders: Cydippidea, Lobata, Cestoidea . Sub-class 2 . Nuda . No Orders . Grade 2 . COELOMOCOELA . Phylum 6 .

Platyelmia (q.v.) . Class I .

PLANARIA (see

PLANARIANS) . Order: Turbellaria . Class 2 . TEMNOCEPHALOIDEA (see appendix to PLANARIANS) . No Orders . Class 3 . TREMATODA (see TREMATODES) . Orders: Heterocotylea, Aspidocotylea, Malacocotylea . Class 4 . CESTODA (see TAPEWORMS) . Orders: Monozoa, Merozoa . Phylum 7 .

Nematoidea . Class' .

NEMATODA (see NEMATODE) . No Orders . Class 2 . CHAETOSOMIDAE (see CHAETOSOMATIDA) . No Orders . Class 3 . DESMOSCOLECIDA (Q.V.) . No Orders . Class 4 . NEMATOMORPHA (Q.V.) .

No Orders . Phylum 8 .

Chaetognatha (q.v.) . No Orders . Phylum 9 . Nemertina . Class . NEMERTINA (q.v.) . Orders: Protonemertini, Mesonemertini, Meta- nemertini, Heteronemertini . Phylum lo . Mollusca (q.v.) . Grade A .

ISOPLEURA . Class' . AMPHINEURA (see

CHITON) . Orders: Polyplacophora, Aplacophora . Grade B . PRORHIPIDOGLOSSOMORPHA . Class 2 . GASTROPODA (q.v.) . Sub-class I . Streptoneura . Orders: Aspidobranchia, Pectinibranchia . Sub-class 2 .

Euthyneura . Orders: Opisthobranchia, Pulmonata . Class 3 .

SCAPHOPODA (Q.V.) . No Orders . Class 4 . LAMELLIBRANCHIA (q.v.) . Orders: Protobranchia, Filibranchia, Eulamellibranchia, Septibranchia . Grade C . SIPHONOPODA . Class 5 . CEPHALOPODA (q.v.) .

Orders : Tetrabranchia, Dibranchia . Phylum II .

Appendiculata . Sub-phylum I . Rotifera (q.v.) . Class . ROTIFERA . Orders : Aspianchnaceae, Melicertaceae, Trochosphaeraceae, Ploimoidaceae, Bdelloidaceae, Floscularaceae,Ploima, Seisonaceae . Sub-phylum 2 . Chaetopoda (q.v.) . Class I . POLYCHAETA .

Orders: Nereidiformia, Cryptocephala, Capitelliformia, Terebelliformia, Spioniformia, Scoleciformia . Class 2 .

OLIGOCHAETA . Orders: .4phaneura, Limicolae, Moniligastres, Terricolae . Class 3 . HIRUDINAE (see LEECH) . Orders: Rhynchobdellidae, Gnathobdellidae, Acanthobdellidae . Class 4 . MYZOSTOMIDA (q.v.) . No Orders . Class 5 . SACCOCIRRIDA .

No Orders . Class 6 .

HAPLODRILI (q.v.) . No Orders . Class 7 . EcHIUROIDEA (q.v.) . No Orders . Sub-phylum 3 . Arthropoda (q.v.) . Grade I . CERATOPHORA . Class' .

PERIPATIDEA (see

PERIPATUS) . No Orders . Class 2 . CHILOPODA (see CENTIPEDE) . Sub-class I . Pleurostigma . Orders: Geophilomorpha, Scolopendromorpha, Craterostigmomorphe, Lithobiomorpha . Sub-class 2 . Notostigma . Order: Scutigeromorpha . Class 3 . DIPLOPODA (see MILLIPEDE) .

Sub-class I . Pselaphognatha . Order : Penicillata . Sub-class 2 . Chilognatha . Orders: Oniscomorpha, Limacomorpha, Colobognatha, Ascospermophora,Proterospermophora, Merochaeta, Opisthospermophora . Class 3 . PAUR.OPODA (see MILLIPEDE) . No Orders . Class 4 . SYMPHYLA (see MILLIPEDE) . No Orders .

Class 5 .

HEXAPODA (q.v.) . Sub-class' . Apterygota . Order: Aptera . Sub-class 2 . Exopterygota . Orders: Dermaptera, Orthoptera, Pleceptera, Isoptera, Corrodentia, Ephemoptera, Odonata, Thysanoptera, Hemiptera, Anoplura . Sub-class 3 . Endopterygota . Orders: Neuroptera, Coleoptera, Mecaptera, Trichoptera, Lepidoptera, Diptera, Siphonaptera, Hymenoptera . Grade 2 .

ACERATA . Class I .

CRUSTACEA (q.v.) . Sub-class I . Entomostraca (q.v.) . Orders: Branchiopoda (Sub-orders: Phyllopoda, Cladocera, Branchiura), Ostracoda, Copepoda . Sub-class 2 . Thyrostraca (q.v.) = (Cirripedia) . No Orders . Sub-class 3 . Leptostraca . No Orders .

Sub-class 4 .

Malacostraca (q.v.) . Orders: Decapoda (Sub-orders: Branhyura, Mac- aura), Schizopoda (including Anaspides), Stoma- topoda, Sympoda (Cumacea), Isopoda (including Tanaidacea), Amphipoda . Class 2 . ARACHNIDA (q.v.) . Grade A . TRILOBITAE (see TRILOBITE) . (Orders not determined.) Grade B . NOMOMERISTICA . Sub-class I . Pantopoda . Orders: Nymphonomorpha, 4scorhynchomorpha, Pycnogonomorpha .

Sub-class 2 . Eu-Arachna . Grade a . Delobrancha (or Hydropneusta) . Orders: Xiphosura, Gigantosiraca . Grade b . Embolobranchia (or Aeropneusta) .

Section . Pectinifera . Order: Scorpionidea . Section . Epectinata .

Orders:

Pedipalpi, Araneae, Palpigradi, Solifugae, Pseudoscorpiones, Podogona, Opiliones, Rhynchostomi (Atari) . Class 3 . TARDIGRADA (q.v.) . No Orders . Class 4 . LINGU.ATALINA (see PENTASTOMIDA) . No Orders . Phylum 12 . Echinoderms (see ECHINODERMS) . Branch A . PELMATOZOA . Class I .

CYSTIDEA . Orders: Amphoridea, Carpoidea, Rhombifera, Aporita, Diploporita . Class 2 . BLASTOIDEA . Divisions: Protoblastoidea, Eublastoidea . No Orders . Class 3 . CRINOIDEA . Orders: Monocyclica Inadunata, Adunata, Monocyclica Camerata, Dicyclica Inadunata, Flexibilia, Dicyclica Camerata . Class 4 . EDRIOASTEROIDEA . No Orders .

Branch B . ELEUTHEROZOA . Class I . HOLOTHUROIDEA . Orders: A s pidochirota, Dendrochirota . Class 2 . STELLIFORMIA . Sub-class 1 . Asterida . Orders: Phanerozonia, Cryptozonia . Sub-class 2 . Ophiurida .

Orders: Sireptophiurae, Zygophiurae, Cladophiurae . Class 3 . ECHINOIDEA . Orders: Bothriocidaroida, Meloniloida, Cystocidaroida, Cidaroida, Diademoida, Holectypoida, Spatangoida, Clypeastroida . Phylum 13 .

Vertebrata (q.v.) . Sub-phylum a . Hemichorda (q.v.) . Class . ENTEROPNEUSTA (see BALA.NOGLOSSUS) . No Orders . Sub-phylum b .

Urochorda . Class .

TUNICATA (q.v.) . Orders: Larvacea, Thaliacea (Sub-orders: Cyclomyaria, Hemimyaria), Ascidiacea (Sub-orders: A scidiae Simplices, A scidiae Compositae, Ascidiae Luciae) . Sub-phylum c . Cephalochorda (see AMPHIOxos) . Class . CEPHALOCHORDA . No Orders . Sub-phylum d . Craniata.I Class I . PISCES (See ICHTHYOLOGY) .

Sub-class I .

Cyclostomata (q.v.) . Orders: Myxinoides (or Hyperotreti), Petromyzontes (or Hyperoartii) . Sub-class 2 . Selachia or Elasmobranchii (see SELACHIANS) . Orders: Pleuropterygii, Acanthodii, Ichthyotomi, Plagiostomi, Holocephali . Sub-class 3 . Teleostoma . Orders: Ganoidea, Crossopterygii, Dipneusii, Teleostei . Class 2 . BATRACHIA (qv.) . Orders: Stegocephalia, Apoda (or Peromela), Caudata • (or Urodela), Ecaudata (or Anura) .

Class 3 . REPTILIA (See

REPTILES) . Orders: Anomodontia, Chelonia, Samopterygia, Ichthyopterygia, Rhyncocephalia, Dinosauria, Crocodilia, Ornithosauria, Squamata . Class 4 . AYES (see BIRD and ORNITHOLOGY) . Sub-class I . Archaeornithes . No Orders . Sub-class 2 . Neornithes . Division I . Ratitae .

Orders: Struthiones, Rheae, Casuariae, Apteryges, Dinornithes, Aepyornithes . Division 2 .

Odontolcae . No Orders . Division 3 . Carinatae . Orders: Ichthyornes, Colymbiformes, Sphenisciformes, Procellariiformes, Ciconiiformes, (Sub-orders: Steganopodes, Ardeae, Ciconiae, Phoenicopteri) . Anseriformes (Sub-orders: Palamedeae, Anseres), Falconiformes (Sub-orders: Cathartae, I Craniata may be usefully divided into 3 grades: (a) Branchiata lieterodactyla, which includes Pisces except Cyclostomes . (b) Branchiata Pentadactyla, which includes Batrachia . (c) Lipobranchia Pentadactyla, which includes Reptiles, Birds and Mammals . 1035 Accipitres), Tinamiformes, Galliformes (Sub orders: Mesites, Turnices, Galli, Opisthocomi), Gruiformes, Charadriiformes (Sub-orders: Linzicolae, Lari, Pterocles, Columbae), Cuculiformes (Sub-orders: Cucuii, Psiltaci), Coraciiformes (Sub-orders: Coraciae, Striges, Caprimulgi, Cypseli, Colii, Trogones, Rid), Passeriformes (Sub-orders: Passeres Anisomyodae, Passeres Diacromyodae) . Class 4 .

MAMMALIA (q.v.) . Sub-class I . 1Vlonotremata (q.v.) (Prototheria) . No Orders . Sub-class 2 . Marsupialia (q.v.) (Metatheria) . One Order: Marsupialia . Sub-orders: Polyprotodonta, Paucituberculata, Diprotodonta . Sub-class 3 . Placentalia (Monodelphia, q.v . ; or Eutheria) . Orders: Insectivore, Chiroptera, Dermoptsra, Edentate (Sub-orders: Xenarthra, Pholidota, Tubulidentata), Rodentia (Sub-orders: Duplicidentata, Simplicidentata), Tillodontia, Carnivora (Sub-orders: Fissipedia, Pinnipedia, Creodonta), Cetacea (Sub- orders: Archaeoceti, Odontoceti, Mystacoceti), Sirenia, Ungulata (Sub-orders: Proboscidea, Hyracoidea, Barypoda, Toxcdontia, Amblypoda, Litopterna, Ancylopoda, Condylarthra, Perissodactyla, Artiodactyla), Primates (Sub-orders: Prosinziae, Anthropoidea) .

Phylum 14 .

Mesozoa (q.v.) . Class I . RIIOMBOZOA . No Orders . Class 2 . ORTHONECTIDA . No Orders . Phylum 15 . Polyzoa (q.v.) . Class I . ENTOPROCTA .

No Orders . Class 2 . ECTOPROCTA . Orders: Gymnolaemata (Sub-orders: Tripostomata, Cryptostomata, Cyclostomata, Ctenostomata, Cheilostomata), Phylactolaemata . Phylum 16 .

Acanthocephala (q.v.) . Class . ACANTHOCEPIIALA . No Orders . Phylum 17 . Podaxonia . Class I .

SIPUNCULOIDEA (q.v.) . No Orders . Class 2 . PRIAPULOIDEA (q.v.) . No Orders . Class 3 . PHORONIDEA (q.v.) . No Orders . Class 4 . PTEROBRACHIA (q.v.) . No Orders . Class 5 .

BRACHIOPODA (q.v.) . Sub-class 1 . Ecardines (Inarticulata) . Orders: Atremata, Neotremata . Sub-class 2 . Testicardines (Articulata) . Orders: Protremata, Telotremata . Phylum 18 . Gastretricha (q.v.) . Class . GASTROTRICHA . Sub-orders: Ichthydina, Cepodina .

(Possibly

Kinorhyncha (q.v.) with only Echinoderes is to be placed here) .