384 



GENERAL ZOOLOGY 



CLASS II. SUCTORIA. Sessile protozoans without cilia 

 except in early stage of development. They are parasitic 

 forms provided with tentacles for piercing or sucking. 



Example : Tokophrya (Fig. 216, B) . One species is frequently 

 found attached to fresh-water copepods, which are small 

 crustaceans. 



B 



D 



Fig. 216. 



-A, Stentor. B, Tokophrya. {After Hertwig.) C, Vorticella. 

 Stylonychia mytilus. {After Stein.) N, macronucleus. 



D, 



METAZOA 



The group Metazoa includes all animals above Protozoa and 

 therefore has the rank of a subkingdom. On this basis Protozoa 

 is both a subkingdom and a phylum. The general features that 

 distinguish Metazoa from Protozoa are as follows: 



1. The body of the Metazoan is composed of many cells that 

 may be divided into two general classes: somatic cells and germ 

 cells. 



2. The somatic cells are differentiated into tissues and organs, 

 in which there is specialization of structure and function. 



