614 



PROTOZOOLOGY 



region; contractile vacuole central; macro nucleus posterior to it; 

 42-50/x long. 



Genus Platynematum Kahl. Ovoid or ellipsoid; highly flattened; 

 with a long caudal cilium; contractile vacuole posterior-right; small 

 cytostome more or less toward right side, with 2 outer membranes; 

 ciliary furrows horseshoe-shaped; in fresh or salt water. 



P. sociale (Penard) (Fig. 290, h). Anterior half more flattened; 

 ventral side concave; cytostome in the anterior third; yellowish and 

 granulated; 30-50jLt long; sapropelic in fresh and brackish water. 



Fig. 290. a, Espejoia musicola, X300 (Penard); b, Cryptochiliduim 

 echini, X380 (Powers); c, Eunjchilum actiniae, X360 (Andr6); d, Mono- 

 chilum frontatum, X440 (Schewiakoff ) ; e, Dichilum cuneiforme, X700 

 (Schewiakoff) ; f, Loxocephalus plagius, X380 (Stokes); g, Balanonema 

 biceps, X600 (Penard); h, Platynematum sociale, X500 (Kahl); i, Sapro- 

 philus agitatus, X450 (Stokes); j, S. muscorum, X440 (Kahl); k, Cineto- 

 chilum margaritaceum, X440 (Kahl). 



Genus Saprophilus Stokes. Ovoid or pyriform; compressed, cy- 

 tostome in anterior 1/4-1/3 near right edge, with two membranes; 

 macronucleus spherical; contractile vacuole posterior; in fresh water, 



S. agitatus S. (Fig. 290, i). Ellipsoid; ends bluntly pointed; com- 

 pressed; plastic; close striation; about 40ju long; in fresh water in 

 decomposing animal matter such as Gammarus. 



