EUCILIATA, HOLOTRICHA 557 



Genus Sieboldiellina Collin Vermiform, with neck-like constric- 

 tion; simple sucker at anterior end. One species. 



S. planariarum (Siebold) (Fig. 265, g). Up to 700/li long; in gastro- 

 vascular cavity of various fresh- and salt-water turbellarians, most 

 frequently Planaria iorva. 



Family 4 Intoshellinidae Cepede 



Genus Intoshellina Cepede. Elongate; ciliary rows slightly spiral; 

 macronucleus voluminous, highly elongate; 5-7 contractile vacuoles 

 scattered in posterior region; a complicated attaching organella at 

 anterior end (Fig. 265, i) ; vestigial cytopharynx. 



/. poljanskyi Cheissin (Fig. 265, h, i). 170-280m long; in the intes- 

 tine of Limnodrilus arenarius. 



Genus Monodontophrya Vejdowsky. Elongate; anterior end with 

 thick ectoplasm; attaching organella at anterior end, with fibrils; 

 macronucleus elongate; numerous contractile vacuoles in a longi- 

 tudinal row. 



M. kijenskiji Cheissin (Fig. 265, j, k). 400-800^ long; in anterior 

 portion of intestine of Tubifex inflaius. 



Genus Maupasella Cepede. Ellipsoid; close longitudinal ciliary 

 rows; with a spinous attaching organella at anterior end, with fibrils; 

 contractile vacuoles in 2 irregular rows; macronucleus elongate. 

 One species. 



M. nova C. (Fig. 266, a). 70-130m long; in the intestine of Alloloho- 

 phora caliginosa (annelid). 



Genus Schultzellina Cepede. Similar to Maupasella; but with at- 

 taching organella set obliquely; macronucleus voluminous, reniform. 



S. mucronata C. (Fig. 266, h). In the intestine of Allurus tetraedurus 

 (annelid). 



Genus Hoplitophrya Stein. Slender, elongate; elongated macro- 

 nucleus; a micro nucleus; a single longitudinal row of many contrac- 

 tile vacuoles on the dorsal side; a single median spicule with a small 

 pointed tooth at its anterior end; in the intestine of oligochaetes. 

 Several species. 



H. secans S. Elongated; 160-500^ by 20-35^; 15-30 contractile 

 vacuoles in a row; spicule 10-15m long; in the intestine of Lwnhricus 

 variegatus. 



Genus Radiophrya Rossolimo. Elongate, often with satellites; 

 attaching organella composed of an arrowhead, a tooth and ecto- 

 plasmic fibrils; macronucleus a narrow long band; a single row of 

 many small contractile vacuoles, close to the nucleus. Many species. 



