HOLOTRICHA 747 



one-fourth from the anterior end; anterior keel with five indenta- 

 tions; 16-18 meridians; in fresh water. 



C. aspera Kahl (Fig. 318, d). 12-42/z long; cytostome about one- 

 third from the anterior end; 14-16 meridians; anterior keel with five 

 indentations; in fresh water. 



C. steini Maupas (Fig. 318, e). 15-42^; cytostome about two-fifths 

 from the anterior end, and with a bundle of long membranellae; five 

 to six preoral ridges; paired and single cilia; one pair of long caudal 

 cilia; 12 meridians; in fresh water. The organism can live in various 

 organs of the land slug, Agriolimax agrestis (Reynolds, 1936). 



C. duodenaria Taylor and Furgason. 20-40/x (9-60m) long; 12 longi- 

 tudinal ciliary rows; 3 postoral rows; 2 long cilia at the posterior 

 end; long cilia project out from the cytostome along its posterior 

 margin, forming a "beard"; a contractile vacuole terminal; macro- 

 nucleus ovoid, with crescentic micro nucleus; division into 2-8 indi- 

 viduals in division cyst; but no division in trophozoite stage; bac- 

 teria-feeder; fresh water. Encystment (Taylor and Strickland, 1939) ; 

 identity (Burt, 1940). 



Genus Tillina Gruber. Similar to Colpoda in general appearance 

 and structure; but cytopharynx a long curved, ciliated tube; in fresh 

 water. 



T. magna G. (Fig. 318, /, g). 180-20G> long (Gruber), up to 400 m 

 long (Bresslau) ; macronucleus oval to rod-shape; micronuclei vesicu- 

 lar, highly variable in number (2-16) (Beers); a contractile vacuole 

 terminal, with six long collecting canals; division cyst produces four 

 individuals; in stagnant water and also coprozoic. Morphology 

 (Gregory, 1909; Beers, 1944, 1945); encystment and excystment 

 (Beers, 1945, 1946, 1946a). 



T. canalifera Turner (Figs. 26; 318, h). 150-200/x by 100-1 50m; 

 resembles magna; but macronucleus ellipsoid, about one-third the 

 body length; four to 14 micronuclei, clustered around the macro- 

 nucleus; a terminal contractile vacuole with seven to nine long 

 permanent collecting canals; cytoplasm with 3-7/x long refractile 

 rods; in fresh water (Turner, 1937). Cytoplasmic inclusions (Turner, 

 1940). 



Genus Bresslaua Kahl. General body form resembles Colpoda; but 

 cytopharynx large and occupies the entire anterior half. 



B. vorax K. (Fig. 318, i). 80-250m long; in fresh water. 



Genus Bryophrya Kahl. Ovoid to ellipsoid; anterior end more or 

 less bent toward left side; cytostome median, about 1/3 from an- 

 terior end, its right edge continues in horseshoe form around the 

 posterior end and half of the left edge; anterior portion of left edge of 



