SPECIAL MORPHOLOGY AND TAXONOMY OF INFUSORIA 403 



2. Thick cortex extends to posterior end 



Genus Collinella 

 Thick cortex on both ventral and dorsal 



sides Genus Pycnothrix 



Family 2. Enchelinidse, Ehrenberg. 



1. With uniform cilia over whole or part of cell 2 

 With one or more girdles of conspicuous 



cilia 22 



2. Axopodial processes in addition to cilia ... 3 

 Without axopodia or other pseudopodia ... 4 



3. Long pseudopodia with axial filaments 



Genus Myriaphrys 

 Short pseudopodia-like processes . . . Genus Dactylochlamys 



4. Body with long caudal hair or hairs 5 



Body without posterior hairs 7 



5. Body uniformly ciliated 6 



Cilia absent from posterior third of body 



Genus Balanitozoon 



6. House- or test-dwelling Genus Pekmiphora 



Without house or test (Fig. 165) . . . Genus Urotricha 



7. With temporary forest of tentacles (Fig. 



81, p. 154) Genus Actinoholus 



Without tentacles 8 



8. Bodj' enclosed in cuirass of plates 9 



Body without covering plates 11 



9. Posterior end truncate; with spines (Fig. 



65, p. 128) Genus Coleps 



Posterior end without spines 10 



10. Posterior end pointed Genus Tiarina 



Posterior end rounded Genus Plagiopogon 



11. With visible gullet and pharyngeal trichites 12 

 Mouth closed, without visible armature. . . 16 



12. Mouth surrounded by circlet of long cilia 13 

 Mouth without special cilia 15 



13. Body flexible, worm-like 14 



Body rigid Genus Metacysiis 



14. Short row of trichocysts down ventral side 



Genus Cranotheridium 

 Without trichocysts; mouth often quad- 

 rangular (Fig. 165) Genus Trachelocerca 



15. Elongate; knob on end of neck-like probos- 



cis Genus Trachelophyllum 



Body spheroidal or elongate; no knob 



(Fig. 165) Genus Prorodon 



16. Mouth circular 17 



Mouth slit-like, covering most of anterior 



end 21 



17. Neck-like constriction with circle of long 



cilia (Fig. 76, p. 148) Genus Lacrymaria 



Without constriction 18 



18. Body elongate, highly metabolic (Fig. 166, 



p. 379) Genus Choenia 



Oval to ellipsoid, neither metabolic nor 

 rigid 19 



19. Mouth region sharply truncated 20 



Mouth region rounded ; lips often tumid . . . 19a 



