384 ZOOLOGY 



INFUSORIA. Protozoa with cilia or sucking tentacles (222). 



[CILIATA]. Locomotor, with cilia: HOLOTRICHA (Parame- 

 cium, 224); HETEROTRICIIA (224) ; PERITRICHA : Vorticella (225). 

 [SUCTORIA]. Sessile, with sucking tentacles (225). 



OELENTERATA 



Animals of radial structure, whose digestive cavity is lined by the 

 body-wall (205). 



[SPONGIARIA] 



Ccelenterata whose body-wall is perforated by incurrent pores (205). 



[CNIDARIA] 



Coelenterata whose body-wall is not perforated by incurrent pores, 

 and which have nettling organs of some sort (205). 



HYDROZOA. Cnidaria whose body is composed of more than two 

 rays and contains a simple cavity. HYDROMEDUS.E, attached Hydro- 

 zoa in hydroid stage ; medusa simple : Hydroidce (208) ; Hydrocoral- 

 lidce (208); Tubularidce (208) ; Campanularidce (209); Traclwmedusce, 

 (Zygodactyla, 212). SIPHONOPHORA, a free swimming colony of 

 Hydrozoa (212). 



SCYPHOZOA. Cnidaria with many radii, and with radial parti- 

 tions in cavity of body (214). 



CTENOPHORA. Cnidaria with only two radii, and rows of cilia- 

 plates (219). 



SCOLECIDA 



Animals of worm-like form, with bilateral, unsegmented body. 



PLATYHELMINTHES. Bilaterally symmetrical, soft-bodied 

 animals, without true segmentation of the body ; flattened in a dorso- 

 ventral direction, and having body-cavity filled with a loose meshwork 

 of cells. TURBELLARIA, free-living flatworms whose body is cov- 

 ered by cilia ; alimentary tract with only one opening to the exte- 

 rior : Planaria (153). TREMATODA, parasitic, without cilia in the 

 adult; the mouth leads into a forked food-canal without anus: Dis- 

 tomum (153). CESTODA, elongated tape-like intestinal parasites, 

 without mouth or food-canal : Tsenia (156). NEMERTIXI, body more 

 or less flattened ; food-canal with mouth and anus ; a separate pro- 

 trusible proboscis (158). 



