THE CLASSIFICATION OF ANIMALS 



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Class I Archiannelida. Primitive marine worms without 

 parapodia or setae. Example: Polygordius. 



Class II Chaetopoda. Bristles along the body. Examples 

 are the earthworm or sandworm. 



Class III Hirudinea. Without bristles and having suckers 

 at both ends of the body. Examples are the leeches. 

 Phylum VIII. MOLLUSCA (Lat., mollis soft). Soft-bodied 

 unsegmented animals, often provided with a shell which is secreted 

 by a part of the body. 



Class I Gastropoda (belly rfoo ted). With or without shells, 

 which, when present, are of one piece and coiled. Snails, whelks, 

 and slugs. 



Class II Pelecypoda (hatchet-footed). Shells in two 

 valves or parts. Clams, oysters, scallops, and mussels. 



Class III Cephalopoda (head-footed) . Foot partly sur- 

 rounds head and bears tentacles or grasping organs. Squids, 

 octopuses, and cuttlefishes. 



Phylum IX ARTHROPOD A (Gr., arthros joint; pous- 

 foot). Animals are segmented, and have chitinous exoskeletons 

 and jointed appendages. They live in water, on land, in the air, 



The reptiles are legless vertebrates with a skin covering made of scale-like plates. 



