SPIROTRICHA, HETEROTRICHA 647 



S. niger (Mliller). Yellowish or brown; macro nucleus oval; 200- 

 300m long. 



S. multiformis (M.) Dark blue to bluish green; anterior end not 

 expanded; 150-200/x long; macronucleus oval. 



S. amethystinus Leidy (Fig. 394, j). Habitually pyriform (con- 

 tracted); amethyst-blue; with zcochlorellae; 300-600/i long; macro- 

 nucleus oval. 



S. pyriformis Johnson. When extended 500/i long; anterior end 

 200m in diameter. 



Genus Fabrea Henneguy. Pyriform; posterior end broadly round- 

 ed, anterior end bluntly pointed; peristome extends down from 

 anterior end 2/5 or more the body length, its posterior portion 

 closely wound; peculiar black spot beneath membranellae in anterior 

 portion of spiral adoral zone, composed of numerous pigment gran- 

 ules; without contractile vacuole; macronucleus, a sausage-shaped 

 body or in 4 parts; in salt water. 



F. salina H. (Fig. 306, a, h). 120-220m by 67-125^ (Kirby); 130- 

 450/x by 70-200/x (Henneguy); cysts ovoidal, with gelatinous enve- 

 lope; 89-IIIm by 72-105^. Kirby (1934) found the organism in 

 ditches and pools in salt marshes, showing salinities 7.5-20.1 per 

 cent in California. 



Genus Climacostomum Stein. Oval; flattened; right edge of peri- 

 stome without membrane, left edge, semicircular or spiral with a 

 strong adoral zone; peristomal field ciliated; cytopharynx a long 

 curved tube with a longitudinal row of cilia; macronucleus band- 

 form; contractile vacuole terminal, with two long canals; fresh or 

 brackish water. 



C. virens (Ehrenberg) (Fig. 306, c). 100-300m long; with or without 

 zoochlorellae; fresh and brackish water. 



Family 6 Folliculinidae Dons 



Genus FoUiculina Lamarck. Lorica attached on broad surface; 

 neck oblique to perpendicular; sometimes with a collar or spiral 

 ridge; neck uniform in diameter; salt water. 



F. moebiusi Kahl (Fig. 306, d). Lorica about 500m long. 



F. producta (Wright) (Fig. 306, e). Lorica yellowish brown; 250m 

 long; neck often long; Atlantic coast. 



Genus Microfolliculina Dons. Posterior end or sides of lorica with 

 sack-like protuberances. 



M. limnoriae (Giard). Lorica dark blue; pellicle faintly striated; 

 salt water. 



Genus Pseudofolliculina Dons. Lorica attached with its posterior 



