PROTOZOA 



11 



Order 4. Peritricha. 



Body globular or cylindrical, only partially ciliated, either near the mouth in a 

 spiral, or in a belt. Forticella (Fig. 16), Carchcsium, Hpistylis, Trichodina, Strom- 

 hidium, Tintinnus, Ophrydmm. 



Fig. 17.— Podophrya genunipara, after R. Hertwig (from Clans's Zoology) ; a, with protruded 

 suctorial tentacles and capturing processes, with two contractile vacuoles; b, with buds into 

 which processes of the branched nucleus N enter ; c, one of the buds broken loose. 



Class VI. Suotoria (Aoineta). 



Ciliated only in swarm-spore stage. With suctorial tentacles, by means of which 

 they penetrate the bodies of Infusoria (principally) and suck in their protoplasm. 

 Reproduction by gemmation. Acineta, Podophrya (Fig. 17), Dendrocmndes. 



Class VII. Catallacta. 



Single genus and species : Mago- 

 sphcera planula (Fig. 18), found 

 swimming freely in the sea on the 

 coast of Norway. A globular colony 

 of pear-shaped cells, the stems of 

 which meet at the centre of the 

 sphere ; the outer surface of the 

 cells provided with cilia. 



Reproduction : the colony dis- 

 solves into single cells, which sink 

 to thebottom, become first amoeboid, 

 then encysted, and make a new 

 colony within the capsule by means 

 of successive division ; this new 

 colony frees itself later from the 

 capsule. 



Fro. 18.— Magosphsera planula, after Haeokel. 



