500 BIOLOGY OF THE PROTOZOA 



Key In Fmii Hies 



5. Spiral zone extends from anterior right to 



posterior left Family 2. Spirozonidae 



Spiral zone extends from anterior left to 



posterior right Family 3. Trichospiridae 



6. Ciliated cross-furrow in anterior half of 



body runs on ventral surface to mouth 



Family 4. Plagiopylidae 

 Ciliated ventral cross-furrow absent 7 



7. Mouth in flat oval longitudinal pit with 



heavy ciliated walls, first quarter 



Family 5. Clathrostomidae 

 Mouth deep, funnel-like 8 



8. Mouth funnel with strong cilia; mouth 



about central at base of diagonal peris- 

 tome Family 7. Parameciidae 



Peristome from anterior end absent 9 



0. Free living, many in moss ; oral funnel deep; 



cilia at top and bottom Family 6. Colpodidae 



Ecto-or endocommensals 10 



10. Ectocommensals (on invertebrates) 11 



Endocommensals in vertebrates (mam- 

 mals) 14 



11. Attaching organs absent Family 10. Conchophthiriidae 



Attaching organs present 12 



12. Attaching organ tentacular. . . .Family 11. Hypocomidae 

 Attaching organs thigmotactic cilia 13 



13. Thigmotactic cilia circumoral. .Family 12. Boveriidae 

 Thigmotactic cilia not circumoral 



Family 13. Ancistrumidae 



14. Entire body covered with cilia 15 



Cilia in certain regions only 16 



15. With "concretion" vacuole. . . .Family 15. Paraisotrichidae 

 Concretion vacuole absent Family 14. Isotrichidae 



16. Mouth occupies entire anterior end; cilia 



limited to mouth region Family 17. Cyathodiniidae 



Mouth not terminal; tufts of cilia above 

 and below mouth and in posterior anal 



region Family 16. Blepharocoridae 



Key to Genera 



Family 1. Schiadostomidae Kahl 1926. 



Only one genus — S. difficile Kahl 

 Family 2. Spirozonidae Kahl 192(1 

 Only one genus — S. caudata Kahl 

 family 3. Trichospiridae Kahl 1926. 

 Only one genus — Trichospira Roux 

 Family 4. Plagiopylidae Schewiakoff 1896. 



1. Peristome a distinctly ciliated groove or 



pit ' 2 



Peristome without groove or pit; with cres- 



centic, protruding and stiff lip. . Genus Sonderiella Kahl 



2. Gelatinous mantle present Genus Sonderia Kahl 



Gelatinous mantle absent; peristome fur- 

 row near edge of dorsal side, forming dis- 

 tinct notch 3 



