806 PROTOZOOLOGY 



organisms exhibit a great variety of form and size in the tadpoles of 

 various frogs, although those of adult frogs are relatively constant 

 in form. Life cycle (Wichterman, 1936) (p. 198) ; tactile cilia (Fernan- 

 dez-Galiano, 1948); fibrillar structure (ten Kate, 1927). 



Family 4 Condylostomidae Kahl 



Genus Condylo stoma Bory. Ellipsoid; anterior end truncate, 

 posterior end rounded or bluntly pointed; slightly flattened; peri- 

 stome wide at anterior end and V-shaped, peristomal field not cili- 

 ated; a large membrane on right edge and adoral zone on left; macro- 

 nucleus moniliform; one to several contractile vacuoles often with 

 canal; cytopyge posterior; fresh or salt water. Many species (Spie- 

 gel, 1926). 



C. vorticella (Ehrenberg) (Fig. 344, d). 100-200/x long; fresh water. 



C. patens (Mtiller). 250-550ju long; salt water; Woods Hole (Cal- 

 kins). 



Family 5 Stentoridae Carus 



Genus Stentor Oken. When extended, trumpet-shaped or cylindri- 

 cal; highly contractile; some with mucilaginous lorica; usually oval 

 to pyriform while swimming; conspicuous peristomal field frontal; 

 adoral zone encircles peristome in a spiral form, leaving a narrow 

 gap on ventral side; the zone and field sink toward cytostome and 

 the former continues into cytopharynx; macro nucleus round, oval or 

 elongated, in a single mass or moniliform; contractile vacuole 

 anterior-left; free-swimming or attached; fresh water. 



S. coeruleus Ehrenberg (Figs. 14; 344, e). Fully extended body 

 1-2 mm. long; anterior end greatly expanded; the beautiful blue 

 color is due to a pigment, stentorin, lodged in interstriation gran- 

 ules (p. 45); macronucleus moniliform; fresh water. Body and nu- 

 clear size (Burnside, 1929); physiology (Dierks, 1926); effect of en- 

 vironment (Stolte, 1922); cytology (Dierks, 1926; Weisz, 1949); re- 

 generation (Schwartz, 1935; Weisz, 1948, 1948a, 1951); vertical dis- 

 tribution (Sprugel, 1951). 



S. striatus Barraud-Maskell. Dark bluish green; funnel-shaped; 

 peristomal edge irregularly undulating; striation conspicuous; macro- 

 nucleus beaded; up to 2.2 mm. long. 



S. polymorphic (Muller) (Fig. 344, /). Colorless; with symbiotic 

 Chlorella 1-2 mm. long when extended; macronucleus beaded; an- 

 terior end expanded. 



S. miilleri (Bory) (Fig. 344, g). Colorless; with zoochlorellae; 2-3 

 mm. long; anterior end expanded; posterior portion drawn out into 



