66 



PROTOZOA 



Fig. 120 



Fig. 121 



Fig. 120 Vorticella nebulifera (from Bronn). 

 Fig. 121 Vorticella patellina (Calkins). 



V. patellina 0. F. Miiller (Fig. 121). Body not annulated, with a 

 very wide oral end ; length .05 mm. : in fresh and saltwater; Woods Hole. 



V. marina Greef. 

 Body annulated, .035 

 mm. long : marine ; 

 Woods Hole. 



3. PYXIDIUM Kent. 

 Stalk short and not 

 contractile; body elon- 

 gate and elliptical, with 

 a small oral end; oral 

 cilia on a disc called 

 the operculum which can 

 close down like a lid. 



P. ramosa Stokes. 

 Length .15 mm.: in 

 fresh water. 



4. RHABDOSTYLA Kent. Like Vorticella but with a short and non- 

 contractile stalk; body bell-shaped or elongate, 



with small oral end. 



R. brevipes (Claparede and Lachmann). 

 Length .1 mm. : in fresh water. 



5. CARCHESITJM Ehrenberg. Richly branched 

 colonies which form visible grayish masses on 

 water plants and often animals; each individual 

 can contract independently: several species; in 

 fresh water. 



0. polypinum (L.) (Fig. 122). Body broad 

 and funnel-shaped and 'about .1 mm. long: com- 

 mon in fresh and salt water. 



6. ZOOTHAMNIUM Ehrenberg. Like Carche- 

 sium, except that the colony contracts as a whole: 

 several species, in fresh and salt water. 



Z. arbuscula Ehr. Body more or less cyl- 

 indrical; length .05 mm.: on water plants in 

 fresh water. 



7. EPISTYLIS Ehrenberg. Like Ehabdostyla, 

 but colonial; whole colony rigid: numerous spe- 

 cies; in fresh and salt water, often on small 

 animals. 



E. flavicans Ehr. (Fig. 123). Body bell-shaped, .1 mm. long: in 

 fresh water. 



Fig. 122 



Carchesium polypinum 

 (Doflein). 



