Haeckel’s Classification of the Animal World
| Unicellular animals (Protozoa) | ||
| 1. Unnucleated | Bacteria Protamæbæ | Monera |
| 2. Nucleated | a. Rhizopoda | Amœbina Radiolaria |
| b. Infusoria | Flagellata Ciliata | |
| 3. Cell-colonies | Catallacta Blastæada | |
| Unicellular animals (Protozoa) | |||
| I Cœlenterata, or Zoophytes. Animals without body-cavity, blood, or anus. | a. Gastræads | Gastremaria Cyemaria | |
| b. Sponges | Protospongiæ Metaspongiæ | ||
| c. Cnidaria (stinging animals) | Hydrozoa Polyps Medusæ | ||
| d. Platodes (flat-worms) | Platodaria Turbullaria Trematoda Cestoda | ||
| II Cœlomaria or Bilaterals. Animals with body-cavity and anus, and generally blood. | a. Vermalia (worm-like) | Rotatoria Strongylaria Prosopygia Frontonia | |
| b. Molluscs | Cochlides Conchades Teuthodes | ||
| c. Articulates | Annelida Crustacea Tracheata | ||
| d. Echinoderms | Monorchonia Pentorchonia | ||
| e. Tunicates | Copelata Ascidiæ Thalidiæ | ||
| f. Vertebrates | I. Acrania-Lancelet (without skull) II. Craniota (with skull) a. Cyclostomes (“round-mouthed”) | ||
| b. Fishes | Selachii Ganoids Teleosts Dipneusts | ||
| c. Amphibia d. Reptiles e. Birds | |||
| f. Mammal | Monotremes Marsupials Placentals: Rodents Edentates Ungulates Cetacea Sirenia Insectivora Cheiroptera Carnassia Primates | ||
(This classification is given for the purpose of explaining Haeckel’s use of terms in this volume. The general reader should bear in mind that it differs very considerably from more recent schemes of classification. He should compare the scheme framed by Professor E. Ray Lankester.)