EDMONDSON — PROTOZOA OF IOWA. 55 



Frontoyiia Ehr. 

 Ophryoglena Ehr. 

 Loxocephahis Eberh . 

 Uronei7ia Duj. 

 Colpidium Stein. 

 Colpoda Miill. 

 '^Dallasia Stokes. 



Elongated, rounded anteriorly, tail-like posteriorly. Mouth 

 near the anterior end with membranes similar to Glaucoma. 



Urocentrid.^. 



Mouth ventral. Cilia in two broad bands encircling the body. 

 Urocentrum Nitzsch. 



MlCROTHORACID^. 



Cilia scattered, mouth in the posterior region. 

 Microthorax Eng. 

 Cmetochilum Perty. 



Param^Ciid^. 



Mouth lateral, preceded by an oblique oral groove. 

 Paramceciuvi Miill. 



Pl^EURONEMID^. 



Mouth at the posterior end of a ventral furrow or peristome. 

 Peristome with undulating membrane or membranes. 

 Lembadion Perty. 

 Cyclidiiim Ehr. 

 Ctcdodema Stokes. 

 "^Pleuroyiema Duj. 

 Slightly larger than Cyclidiiim. No posterior setae. 



Cyrtolophosiid^. 



Body at times enclosed within a soft mucilaginous envelope 

 secreted by itself. Mouth at the end of a short furrow. A tuft 

 of cilia at the anterior extremity. 



CyrtolopJiosis Stokes. 



Families and Genera of Heterotricha. 



Plagiotomid^:. 



Mouth near or posterior to the middle of the body, preceded by 

 a narrow peristomal furrow. 



