Euplectella Cbalina oaslata 



Euspongia 

 oflicinalia 



Coral 

 ICoralhum zubnia) 



Sea walnut 

 (PkuiobracbtQ pileu$) 



CLASS 3 INFUSORIA ("poured into"). Move and feed by vibrating hair- 

 line projections called cilia, which extend through the tough outer covering; 

 abound in hay-infusions. 



CLASS 4 SPOROZOA ("spore animals"). Parasite forms; produce spores 

 at some stage in the life cycle; malaria fever, Texas cattle fever, and the silk- 

 worm disease pebrine are caused by representatives of this group (see illustra- 

 tions, p. 622). 



PHYLUM II PORIFERA ("pore-bearing"). Consist of innumerable similar 

 cells supported on a porous calcareous, siliceous, or horny skeleton; mostly 

 marine. 



PHYLUM III COELENTERATES ("hollow mtestine"). Radially symmet- 

 rical animals having a single cavity in the body; all aquatic, mostly marine; 

 many have a marked alternation of generations in their life cycle. 



CLASS 1 HYDROZOA ("water animal"). Exatnples, fresh-water hydra, 

 certain small jellyfish (see illustrations, pp. 274 and 384). 



CLASS 2 ANTHOZOA ("flower animal"). Examples, most sea-anemones, 

 most corals (see illustration, p. 92). 



CLASS 3 SCYPHOZOA ("cup animals"). Examples, most of the larger 

 jellyfish. 



CLASS 4 CTENOPHORE (ten'ofor, "comb-bearer"). Examples, comb 

 jellies and sea walnuts. The ctenophores differ from the coelenterates in 

 many essentials and are sometimes classed as a separate phylum. 



PHYLUM IV FLATWORMS (Platyhelminthes, "flat worms"). Ribbonlike 

 soft-bodied animals without skeleton; many are parasitic. Examples, tapeworm, 

 liver fluke, planarians (see illustrations, pp. 615 and 229). 



PHYLUM V ROUNDWORMS (Nemathelminthes, "thread worms"). Small 

 cylindrical, soft- bodied animals without skeleton, unsegmented, both parasitic 

 and free-living forms (see illustration, p. 615). Examples, hookworm, trichina, 

 ascaris, thorn-headed worm. 



Anthocepbala 



Ascaris 



Tnchinella 



Case building rotifer 



{FloscuJaiia) 



Glass worm 



692 



