66 



PROTOZOA 



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

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



V. marina Greef. 

 Body annulated, .035 

 nnn. long: marine; 

 Woods Hole. 



3. Pyxidium Kent. 

 Stalk short and not 

 contractile; body elon- 

 gate and elliptical, with 

 I a small oral end; oral 



/ cilia on a disc called 



I the operculum which can 



close down like a lid. 



P. ramosa Stokes. 

 Length .15 mm.: in 

 fresh water. 

 Like Vorticella but with a short and non- 



Fig. 120 



Fig. 121 



Fig. 120 — Vorticella nehuUfera (from Bronn). 

 Fig. 121 — Yortictlla patellina (Calkins). 



4. Rhabdostyla Kent, 

 contractile stalk; body bell-shaped or elongate, 

 with small oral end. 



R. brevipes (Claparede and Lachmann). 

 Length .1 mm.: in fresh water. 



5. Carchesium Ehrenberg, Richly branched 

 colonies which form visible grayish masses on 

 water plants and often animals; each individual 

 can contract independently: several species; in 

 fresh w^ater. 



C. 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 Rhahdostyla, 

 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. 



F'ig. 122 



Carchesium polypinum 

 (Doflein). 



