MORPHOLOGY AND TAXONOMY OF THE INFUSORIA 493 



Family I. Holophryidae Perty 1852. 



8. Body ovoidal to cylindrical with ventral 



inclination; with snout-like oral process 



Genus Lagenophrya Kahl 

 Body otherwise 



9. Mouth a short slit, directed backwards 



from pole; no trichocysts Genus Microregma Kahl 



Mouth not a short, open slit 10 



10. Mouth with 3 closely placed rows of small 



bristles (dorsal brush), no oral papillae. 11 

 Mouth without 3 bristles, some with 1 ; 

 some with widely spread bristles 13 



1 1 . Mouth polar ; slit-like ; usually closed ; outer 



ends of gullet trichocysts not deeply sunk 



Genus Pseudoprorodon Blackburn 

 Mouth slit-like; gullet surrounded by 

 double trichites which end deep in oral 

 ectoplasm 12 



12. Ectoplasm surrounding the mouth flat 



(Fig. 202) Genus Prorodon Ehr. 



Ectoplasm surrounding the mouth slightly 



raised Sub-genus Rhagadostoma Kahl 



13. Ovoid or short cylindrical; neither elong- 



ate nor flask shape; broad truncated an- 

 terior end absent 14 



Elongate, lance-like cylindrical flask-shape ; 

 or worm-like; broad truncated oral end 

 in shorter forms 18 



14. Gullet opening surrounded entirely or in 



part by small papillae 15 



Gullet opening not surrounded by papillae . 16 



15. Posterior end with one or several caudal 



tail cilia, otherwise not ciliated. . .Genus Urotricha C. and L. 

 Posterior end ciliated, no caudal cilia 



Genus Spasmostoma Kahl 



16. Small; oval; mouth with papillae on right 



side, running into short ventral groove 



Genus Plagiocanvpa Schew. 

 Mouth opening flush with body or slightly 

 raised 17 



17. Mouth opening flush with body. . . .Genus Holophrya Ehr. 

 Mouth opening slightly raised. .Sub-genus Balanophrya Kahl 

 Ectoparasitic on fish Sub-genus Ichthyophthirius Fouquet 



18. Elongate, lance-like or flask-shape; much 



flattened, usually with 2 nuclei 19 



Not flattened ; elongate to worm-like, nuclei 

 diverse 20 



19. With long tentacle-like process from ter- 



minal mouth Genus Ileonema Stokes 



Without tentacle-like process Genus Trachelophyllum C. and L. 



20. With annular furrow near anterior end, 



making a head part with spiral rows of 



cilia (Fig. 85) Genus Lacrymaria Ehr. 



Without annular furrow and head part. . . 21 



