CILIATE PROTOZOA (INFUSORIA) 



285 



114 



Without an undulating membrane in the peristome. Body purse- 

 shaped, oblique in front; peristome funnel-shaped, open 

 ing on the ventral side by a slit reaching as far as the 

 middle of the body. Membranellae on the left side of 



the peristome Bursaria Miiller. 



Representative species. 



Bursaria truncatella Miiller 1786. 



Nucleus band-like; contractile vacuoles numerous. Length 500 

 to 700 M- Pond water. 



FIG. 511. Bursaria truncatella. cv, contractile vacuole; macn, macronucleus. 

 X 35- (After Kent.) 



115 (106) Peristome confined to the anterior border of the body, with its 

 plane nearly at right angles to the longitudinal axis of the 

 body 116 



116 (119) 



117 (118) 



118 (117) 



Posterior end not produced into a tail-like process. . 



117 



Body purse-shaped, slightly flattened, anterior end oblique. 



Peristome enclosing most of the anterior end of the body. 



Climacostomum Stein. 



Body funnel-shaped when extended, fixed or free-swimming, some- 

 times enclosed in a jelly-like lorica. Peristome, the ante- 

 rior expanded surface with a spiral row of strong cilia 

 around its border; the left end of the spiral being the lower, 

 leading into the mouth and short pharynx. Surface finely 

 ciliate sometimes bearing, in addition, long slender bristles. 



Stentor Oken. 

 Representative species. Stentor poly morphus Miiller 1786. 



Body usually containing a cortical layer of chlorophyl granules. 

 Nucleus moniliform. Length, extended, 1 200 /*. Among aquatic plants 

 and in infusions. Sometimes found in gelatinous masses on leaves and 

 roots of water plants. 



Another fresh-water form, Stentor coeruleus Ehrenberg, blue in color, 

 is also common. 



FIG. 512. 



Stentor polymorphus. cv, contractile vacuole; macn, macronucleus. 

 X 30. (After Kent.) 



119 (116) Posterior end produced into a tail-like process; anterior region 

 helmet-like, rounded anteriorly with a free posterior margin. 

 Mouth ventral in a ciliated groove. Cilia extending from 

 the mouth in a spiral across the anterior border and around 

 the free margin of the anterior portion. 



Caenomorpha Perty. 

 Representative species. Caenomorpha medusula Perty 1849. 



Movements swift, rotating on the long axis. 

 100 to 130 ft. Standing water. 



Length, with tail, 

 FIG. 513. Caenomorpha medusula. X 200. (After Stein.) 



1 20 (105) Cilia restricted to certain limited areas or zones. 



121 (124) Body not in a lorica 



121 

 122 



