EDMONDSON — PROTOZOA OF IOWA. 6 1 



half the length of the body, straight. Nucleus central. Con- 

 tractile vesicle posterior. 



Length of body, 35 microns. (Fig. 91, PI. XII.) 



This species of Urotricha has been found in Johnson county, 

 associated with Cyclidiuiii glaucoma. 



It differs from Urotricha lagoiida I{hr. (not observed in this 

 state) in the inflation of the anterior region and the short length 

 of the springing hair. The oral opening has two protruding lip- 

 like processes and is capable of very wide expansion during the 

 process of ingestion of food. Its breadth when expanded may 

 almost equal the greatest width of the body. When closed the 

 lip-like protrusions meet, one, however, being decidedly shorter 

 than the other. The organism has the habit of a scavenger, dead 

 protoplasm serving as its chief food. 



A central spherical nucleus may be observed by the aid of 

 reagents and a single contractile vesicle is present in the posterior 

 region. 



In its movement the species usually rotates on its longitudinal 

 axis, the springing action not being so noticeable as in Urotricha 

 p/atystoDia, 



Reproduction takes place by transverse fission. 



ENCHELYODON C. & L- 



Body ovate, rounded posteriorly, narrower anteriorly but not 

 produced into a neck-like extension. Oral aperture terminal, fol- 

 lowed by a pharynx which is striated in a longitudinal direction. 



EnCHELYODON FARCTUvS C. & ly. 



Body oval, narrower anteriorly and often slightly curv-ed. 

 Pharynx conspicuou.s and can be traced for some distance within 

 the endoplasm. Nucleus band-like, long and curved. Contrac- 

 tile vesicle posterior. Endoplasm transparent. 



Length, 220 microns. (Fig. 92, PI. XII.) 



Enchclyodo)i farctus has been found abundantly in Johnson 

 county in infusions of pond water. 



Reproduction is by transver.se fission. 



PRORODON Ehrenberg. 



Usually oval, sometimes slightly flattened, evenly rounded at 

 both extremities. Mouth terminal or sub-terminal; pharynx 



