Survey of the Animal Kirigdom 279 



Examples: Paramecium (Figs. 78, 163, 170, and 171), Vorticella (Figs. 78, 

 79, and 80), Stentor (Fig. 78), Lacrymaria (Fig. 78); Prorodon (Fig. 78), 

 Didinium (Fig. 78), Lionotus (Fig. 78), Urocentrum (Fig. 78), Frontonia (Fig. 

 78), Colpoda (Fig. 78), Opalina (Fig. 265), Spirostomum (Fig. 78), Bursaria 

 (Fig. 258), Balantidium (Fig. 262), Halteria (Fig. 78), Stylonichia (Fig. 78), 

 Euplotes (Fig. 78), Carchesium (Fig. 78). 



Subclass B — Suctoria (suk-to'ria) (L. suctum, suck or attach). — The 

 adults are sedentary and without cilia, but they have tubelike sucking structures 

 with which to secure food. The immature larval stage is ciliated; hence, free 

 swimming; eventually it attaches itself and transforms into an adult. 



Example: Podophrys (Fig. 78). 



Cilia 



J'" 



Macronucleus 



Undulating rnewbrane 



CorttractUe vacuole 



Micronudeus 



Pharynx 



food vacuoles 



Stalk 



M\^onQrY)e with elaibic fibres 



Point of attachment 



Fig. 79. — Vorticella, a protozoan of the class Infusoria, subclass Ciliata (highly 



magnified) . 



Phylum 2. Porifera (po-rif'era) (L. porus, a pore; ferro, to bear) 



General Characteristics 



This phylum includes all the animals known as sponges. They all contain 

 systems of canals which are connected with pores located in the body wall. 

 Sponges are multicellular and usually have irregular habits of growth. Depend- 

 ing upon the species, they have either radial symmetry (Scypha) (Grantia) or 

 asymmetry (commercial sponges). With the exception of about fifty species, most 



