SPECIAL MORPHOLOGY AND TAXONOMY OF INFUSORIA 407 



3. With one caudal filament 4 



Without caudal filament 5 



4. Peristome narrow, short, body ellipsoid 



(Fig. 168, p. 385) Genus Cyclidium 



Peristome narrow; two pseudomembranes; 

 elongate (Fig. 170) Genus Lembus 



5. Free-living; peristome long and deep. .... 6 

 Commensal or ectoparasitic 9 



6. With balloon or sail-like membrane 7 



One pseudomembrane of long cilia; spindle- 

 shape Genus Blepharostoma 



7. Special cilia adapted for attachment 10 



Without special attaching cilia 8 



8. Peristome occupies most of ventral surface 



(Fig. 77, p. 149) Genus Lembadion 



Ellipsoidal with one sail-like membrane 



(Fig. 169, p. 385) Genus Pleuronema 



9. Kidney-shape; ectoparasitic on hydroids 



Genus Pleurocoptes 

 Flat; four or five lines of cilia; commensal 

 on Gammarus Genus Larvulina 



10. Ellipsoidal; attaching cilia posterior end. . 11 

 Spherical; peristome turned up; five rows 



cilia Genus Hemispira 



Urn-shape; no cilia; two concentric mem- 

 branes Genus Hemispiropsis 



11. Pseudomembrane spiral at anterior end. 



Genus Boveria 

 Membrane lateral, not spirally wound 



Genus Ancistrum 

 Family 5. Paramecidse, Biitschli. 



One genus with family characteristics (Fig. 



170, p. 385) Genus Paramecium 



Family 6. Isotrichidse, Biitschli. 



Parasitic in mantle fluids of bivalves . . Genus Conchophthirus 

 Parasites of fore-stomach of ruminants . Genus Isotricha 



Genus Dasytricha 



Order II. HETEROTRICHIDA, Stein. 



1. Adoral zone not parallel with main body 



axis 2 



Adoral zone parallel with main body axis 3 



2. Body ellipsoidal or trumpet-shape 



Family 1. Stentorid^ 

 Aledusa-shape ; with manubrium-like pos- 

 terior end Family 4. Gyrocorycid^ 



Discoid; laterally compressed. . .Family 5. Ctenostomid^ 



3. Peristome wide, in,sunk, and usually deep 



Family 2. Bursarid.e 



Peristome narrow and long Family 3. Pl.\giotomid^ 



Family 1. Stentoridae, Stein. 



1. Bod.y not trumpet-shape 2 



Body when expanded, trumpet-shape (Fig. 



74, p. 145) Genus Stenlor 



2. Frontal field drawn out into long arms (Fig. 



81, p. 160) Genus Folliculina 



Frontal field not drawn out 3 



