SPECIAL MORPHOLOGY AND TAXONOMY OF INFUSORIA 381 



5. Tiarina, with cuirass of plates posterior end pointed. 



6. Plagiopocion , longitudinal plates; without spines. 



7. Choenia, highly plastic; mouth circular; no proboscis (Fig. 



16G, p. 379)'. 



8. Lacri/))taria, with neck-like constriction bearing circlet of 



cilia (F'ig. 7(), p. 148). 



9. TrachelophylluDt, very elongate; knob at end of neck-like 



region. 



10. Trachelocerca; flexible, with circlet of cilia, no constriction. 



11. Metacystis, similar to 10 but not flexible. 



12. Lagynus, anterior sharply truncate; body ellipsoidal. 



13. EncheJys, anterior sharplv truncate; bodv flask-shape (Fig. 



160, C). 



14. Spathidiinn, mouth an oblique slit occupying entire anterior 



end (Fig. 90, p. 181). 



15. Monodinium, cilia reduced to one girdle about proboscis 



(Fig. 75, p. 146). 



16. Didiniiim, cilia reduced to two girdles (Fig. 88, p. 179). 



17. Balanitczoon, cilia absent from posterior third of body. 



18. Mesodininm, one central girdle of cilia (Fig. 163, p. 372). 



19. Pelamorpha, test-dwelling; body with posterior filaments. 



20. Urotricha, uniformly ciliated with caudal bristle (Fig. 165, E). 



21. Myriaphrys, with cilia and axopodial pseudopodia. 



22. Dacfylochhiniys, cilia and lobopodia; sapropelic. 

 For other Genera see Key. 



Family 2. Trachehnidse, Fhrenberg, Stein. — Generalized forms 

 with a uniform coating of cilia and with the anterior end drawn out 

 in the form of a proboscis. The mouth may be a slit on the ventral 

 side of the proboscis or a circular opening on dorsal ( TracheJius) or 

 ventral surface {Dilcptus, etc.). Reduction of cilia confined to com- 

 paratively few forms (Lionotus, LoxophiiUum) . Figures pages 378, 

 379, 380.* 



Connuon (leiwra: Lo.rode.s, with an indefinitely indicated probos- 

 cis; TracheJius, with a short and abrupt proboscis: Lionutus and 

 Amjyhileptus with the mouth in the form of an elongated slit extend- 

 ing the entire length of the proboscis; Dikptvs with circular mouth 

 at the base of the proboscis, and Lo.rophyUum with flattened body 

 and short slit-like mouth, and without definite proboscis. 



Family 3. Chlamydodontidse, Stein, Biitschli. — Generally flattened 

 forms with cilia reduced to the right side which, bearing the mouth, 

 is the functional ventral side. The mouth is surroimded by a 

 basket-work of trichites the bases of which extend deeply into the 

 endoplasm. 



Commofi Genera: (For other genera see Key.) 

 1. Nassula (Fig. 13, p. 35), body ellipsoidal or only slightly 

 flattened. 



