HOLOTRICHA 519 



cysts and often undulating; dorsal seam narrow and near its 

 edge, groups of trichocysts in wart-like protuberances; macro- 

 nucleus divided into small ellipsoidal parts; micronuclei, of the 

 same number (Penard) ; contractile vacuole terminal, with a long 

 canal; 300-400^ long, up to 700/x (Penard); feeds mainly on 

 rotifers; fresh water, 



L. setigerum Quennerstedt (Fig. 238, e). 100-350^ long; average 

 150^1 by 60m; form variable; 1-4 macronuclei; several contractile 

 vacuoles in a row; salt and brackish water. 



Genus Bryophyllum Kahl. Similar to Loxophyllum; but uni- 

 formly cihated on both broad surfaces; ventral ridge with closely 

 arranged trichocysts, extends to the posterior extremity and ends 

 there or may continue on the opposite side for some distance; 

 macronucleus ovoid to coiled bandform; in mosses. 



B. (Loxophyllum) vorax (Stokes) (Fig. 238, /). Elongate; 

 trichocyst-bearing ventral ridge turns up a little on dorsal side; 

 contractile vacuole posterior; macronucleus oval; 130/x long; in 

 fresh water among sphagnum and mosses. 



Genus Kentrophoros Sauerbrey. Extremely elongate, nema- 

 tode-like; anterior end greatly attenuated; posterior end pointed; 

 body surface longitudinally striated; ciliation uniform; 1-3 

 macronuclei; numerous contractile vacuoles in 2 rows; cytostome 

 not observed. 



K. fasciolatum S. (Fig. 238, g, h). About 270m by 38m. Noland 

 (1937) observed 2 specimens in sediment taken from sandy bot- 

 tom in Florida; contracted 650m long; extended 1 mm. long. 



Family 2 Tracheliidae Kent 



Genus Trachelius Schrank. Oval to spherical; anterior end 

 drawn out into a relatively short finger-like process or a snout; 

 posterior end rounded; round cytostome at base of neck; cyto- 

 pharynx with trichites; contractile vacuoles many; macronucleus 

 simple or band-form; fresh water. 



T. ovum Ehrenberg (Fig. 239, a). Spheroidal to ellipsoid; right 

 side flattened and with a longitudinal groove; left side convex; 

 proboscis about 1/4-1/2 the body length; ciha short and closely 

 set; numerous contractile vacuoles; macronucleus short sausage- 

 form, often divided into spherules; endoplasm penetrated by 

 branching cytoplasmic skeins or bands and often with numerous 

 small brown excretion granules; 200-400m long; fresh water. 



