A SYNOPSIS OF ANIMAL CLASSIFICATION. 



I. MAIN SUBDIVISIONS OF ANIMALS. 



All known animals, both recent and fossil, may be conveniently 

 grouped in the following eight subdivisions, or Types : 



Type I. PROTOZOA Amoeba, Infusoria, monads, etc. 



Type II. C(ELENTERATA . . . .Hydroid polyps, jelly-fish, corals, 



sponges, etc. 



Type III. VERMES Unsegmented worms, both free 



and parasitic ; rotifers, brachio- 

 pods, etc. 



Type IV. MOLLUSCA Bivalves, like clams and oysters; 



snails and slugs ; cuttlefish, squid, 

 etc. 



Type V. ARTICULATA Segmented worms like earth- 

 worms and leeches ; crustaceans, 

 insects, spiders, mites, etc. 

 Type VI. ECHIKODERMATA.. Star-fish, sea-urchins, etc. 



Type VII. PREVERTEBRATA.-Balanoglossus, tunicates, Amphi- 



oxus. 



Type VIII. VERTEBRATA Fishes, amphibians, reptiles, birds, 



and mammals. 



The idea of thus arranging animals in Types or fixed groups de- 

 veloped mainly under the influence of Linnseus, Cuvier, and Agassiz, 

 who taught that each Type was in itself absolutely distinct from all 



