56 DAVENPORT ACADEMY OF SCIENCES. 



Blepharisma Perty. 

 Metopns C. & L. 

 Metopides Quenn. 

 Spirostomnvi Ehr. 



BURSARID^. 



Peristome a broad, triangular depression, sometimes with a con- 

 spicuous undulating membrane. 



Co?idylostoma Duj. 



'^Biirsaria Miill. 



Body short, sac-like, obliquely truncate in front, flattened ven- 

 trally, convex dorsally. Peristome funnel-shaped, reaching to 

 the middle of the body. 



Stentorid.^. 



Peristome occupying the front border. Mouth in the margin 

 of the peristome, with strong adoral cilia spirally disposed. Body 

 entirely ciliate. 



Stentor Oken. 



Gyrocorid^. 



Oval or pear-shaped, with one or two spiral wreaths of strong 

 cilia. A style-like posterior process often present. 



Gyrocoris Stein. 



Halteriid.^. 



Body with an anterior ring of cilia. Sometimes a posterior 

 circle is also present or an equatorial wreath of springing hairs. 



Halteria Duj. 



^Sirombidiu))i C. & L. 



Similar to Halteria but without springing hairs. Oral cilia 

 very strong. 



Families and Genera of Hypotricha. 



oxytrichid^. 



Cilia of the ventral surface usually fused into styles or setae 

 arranged in series, as frontal, ventral, anal, caudal, and marginal. 

 One or more of these series may be wanting. 



Urostyla Ehr. 



