SPIROTRICHA, HETEROTRICHA 



577 



marginal zone of about 8 rows of cilia; 1-2 dorsal rows of longer 

 cilia and a dense spiral field around caudal prolongation; peri- 

 stome long; cytostome posterior; cytopharynx directed anteri- 



FiG. 262. a, Metopus es, X260 (Kahl); b, M. striatus, X220 (Kahl); 

 c, M. fuscus, X150 (Kahl); d, M. circumlahens, X370 (Powers); 

 e, Spirorhynchus verrucosus, X360 (Kirby); f, Caenomorpha medusula, 

 X200 (Blochmann); g, Blepharisma lateritium, Xl60 (Penard); h, B. 

 persicinum, X290 (Penard); i, B. steini, X340 (Penard); j, Protocruzia 

 pigerrima, X390 (Faria, da Cunha and Pinto); k, Phacodinium 

 metschnicoffi, X270 (Kahl). 



orly; a single elongate or 2 spherical macronuclei; a micronucleus; 

 fresh or salt water (sapropelic). Several species. 



C medusula P. (Fig. 262, /). 150^ by 130^; fresh and brackish 

 water. Several varieties. 



