STEUCTUEE AND CLASSIFICATION OF PEOTOZOA 15 



includes the Foraminifera, since the sarcode body of 

 these animals is capable of free extrusion, as distin- 

 guished from those protozoa with a definite cortex or 

 covering. Class VI. comprises the Eeticularia, which 

 are chiefly marine types ; examples of the fresh- water 

 types are Gromia and Diaplioro'poclon. This group 

 takes its name from the fact that the prolongations 

 of sarcode emitted by the organism form a reticulum 



GREGARINA 



NOCTILUCA 



VORTICELLA 



CERATIUM 



Fig. 12. — Types of Protozoa — Corticata. 



of anastomosing threads. These sarcode extensions 

 entrap minute organisms or other food particles, 

 which are drawn to the mouth of the test, or may 

 even enter it, there to be assimilated. This 

 reticulated character of the extruded sarcode is very 

 distinct from that of the true Lohosa, with which, 

 however, they are grouped in another classification 

 as Khizopoda (Dujardin), and which have finger-like 

 prolongations with rounded tips. These two groups 



