578 PROTOZOOLOGY 



Family 3 Spirostomidae Kent 



Genus Spirostomum Ehrenberg. Elongated; cylindrical; some- 

 what compressed; ectoplasm with highly developed myonemes 

 which are arranged lengthwise independent of ciliary rows, hence 

 highly contractile; yellomsh to brown; excretory vacuole terminal 

 large, with a long dorsal canal; macronucleus either ovoid or 

 chain form; cilia short; rows longitudinal; caudal cilia are thigmo- 

 tactic, secrete mucous threads (Jennings) ; peristome lined closely 

 with short membranellae ; fresh or salt water. Several species. 



S. amhiguum E. (Fig. 263, a). 1-3 mm. long (length: width, 

 10:1); macronucleus chain-form; peristome 2/3 the body length; 

 fresh water. 



S. minus Roux (Figs. 36; 263, h). 500-800^ long; macronu- 

 cleus chain-form; in fresh and salt water (Kahl). 



S. loxodes Stokes (Fig. 263, c). About 300/x long (length : width, 

 6-7:1); peristome about 1/3 the body length; obhque striation 

 longer cilia at ends; macronucleus chain-form; fresh water. 



S. intermedium. Kahl (Fig. 263, d). Slender; 400-600^ long 

 macronucleus chain-form; fresh water. 



S. teres Claparede et Lachmann (Fig. 263, e). 150-400/i long 

 macronucleus oval; in fresh w^ater and also reported from salt 

 water. 



S. filum (E.) (Fig. 263, /). Peristome 1/4 the body length; pos- 

 terior end drawn out; 200-300// up to 700/x long; fresh water. 



Genus Gruberia Kahl. Similar to Spirostomum. in general ap- 

 pearance; but posterior end drawn out; slightly contractile; con- 

 tractile vacuole posterior; macronucleus compact or beaded; salt 

 water. 



G. calkinsi Beltran (Fig. 263, g). 200-800/^ long; peristome 2/3 

 the body length; many (contractile ?) vacuoles distributed; 

 Woods Hole. 



Genus Blepharisma Perty. Pyriform, spindle-form or ellipsoid; 

 somewhat narrowed anteriorly; compressed; peristome on left 

 border, which is twisted to right at posterior end and connected 

 with oral funnel with membrane; in front of cytostome a 2-lay- 

 ered undulating membrane on right edge; ciliary rows longitudi- 

 nal; ciliation dense; contractile vacuole and cytopyge terminal; 

 macronucleus one or divided into several parts; several species 

 rose-colored; fresh or salt water. Many species. 



B. lateritium (Ehrenberg) (Fig. 262, g). 130-200/x long; pyri- 



