CLASSIFICATION 437 



Class MASTIGOPHORA ( ). Protozoa with 



one or more vibratile processes (flagella) which serve for locomotion and 

 for taking food. Euglena. 



Class SPOROZOA ( ). Parasitic Protozoa, 



usually without motile organs or mouth, reproducing by spores. 



Class INFUSORIA ( ). Protozoa having 



numerous slender vibratile processes (cilia), a cuticle, and fixed openings 

 for the ingestion of food and the extrusion of indigestible matter. Para- 

 moecium. 



Phylum PORIFERA ( ). Diploblastic, radially 



symmetrical animals with body w r all penetrated by numerous pores. 

 Body usually supported by a skeleton of spicules or spongin. Sponges. 



Class CALCAREA ( ). Sponges with spicules 



composed of calcium carbonate, monaxon or tetraxon in form. 



Class HEXACTINELLIDA ( ). Sponges with 



spicules composed of silicon, triaxon in form. 



Class DEMOSPONGIAE ( ). Sponges with 



spicules composed of silicon, not triaxon in form, or skeleton composed 

 of spongin, or with skeleton of both spicules and spongin. 



Phylum COELENTERATA ( ). Diploblastic, 



radially symmetrical animals with tentacles, stinging cells, single gastro- 

 vascular cavity, no anus. Two body forms are prevalent, the hydroid 

 and the medusa. Jellyfishes, polyps and corals. 



Class HYDROZOA ( ). Coelenterates without 



stomodaeum and mesenteries; sexual cells discharged to the exterior; 

 hydroid and medusa forms in the life history of same species, or only the 

 medusa, the latter having a velum. Polyps (including Hydra), a few 

 corals, small Jellyfishes. 



Class SCYPHOZOA ( ). Coelenterates with 



only the medusoid, not hydroid form ; velum lacking ; notches at margin 

 of umbrella. Larger Jellyfishes. 



Class ANTHOZOA ( ). Coelenterates without 



medusoid forms, with well developed stomodaeum and mesenteries. Sea 

 anemones, most corals. 



Phylum CTENOPHORA ( ). Tripoblastic 



animals ; symmetry partly radial, partly bilateral ; eight rows of vibratile 

 plates radially arranged. Sea walnuts or comb jellies. 



Phylum PLATYHELMINTHES ( ). Triplo- 



blastic, bilaterally symmetrical animals with body flattened, with a single 

 gastrovascular cavity (sometimes wanting) and no anus. Flatworms. 



Class TURBELLARIA ( ). Free-living flat- 



worms with ciliated epidermis. Planaria. 



Class TREMATODA ( ). Parasitic flatworms 



without cilia but with a hardened ectoderm, usually parasitic and with 

 attaching suckers. Flukes. 



