EDMONDSON — PROTOZOA OF IOWA. II5 



free-swimming ciliates, transferring their contents to the Suctor- 

 ian's body by means of the central axial protoplasmic current. 



Reproduction takes place by transverse division, and on one 

 occasion an internal embryo was observed to break from the par- 

 ent bod}^ being entirely ciliate, but so minute and rapid in its 

 movements that no satisfactory study of it could be made. 



PODOPHRYA Ehrenberg. 



Spherical, oval or elongated pear-shaped. Usually attached by 

 a rigid stalk. Tentacles mostly capitate either in fascicles or dis- 

 tributed irregularly over the periphery. Nucleus and contractile 

 vesicles conspicuous. 



PODOPHRVA FIXA Miill. 



Body spherical, attached by a slender but rigid stalk. Tenta- 

 cles capitate, slender, and scattered over the surface of the body, 

 often not greater in length than the diameter of the body. Nu- 

 cleus oval, central or sub-central. Contractile vesicles sometimes 

 two in number. 



Diameter of body, 55 microns. (Figs. 208-210, PI. XXIX.) 



Found in fresh water among algae, usually attached to aquatic 

 plants by means of the stalk, which rarely exceeds in length the 

 diameter of the body. When the water becomes slightly stag- 

 nant the individuals rapidly pa.ss into the encysted state, the cyst 

 being very characteristic of the species. Beginning with the stalk 

 itself the outer surface gradually becomes indurated and sharp 

 annular ridges make their appearance, there being from four to 

 six in the complete cyst. The pedicle in the completely encysted 

 form has assumed the appearance of a short, curved, caudal ap- 

 pendage. 



Reproduction commonly takes place by transverse division. 

 Fig. 208 illustrates a normal individual. Fig. 209 represents the 

 beginning of the encystment, while Fig. 210 pictures the com- 

 pleted cyst. Small holotrichous forms serve as the principal food 

 of this organism. 



PODOPHRYA QUADRIPARTITA C. & L. 



Body elongate, pear-shaped, the anterior extremity produced 

 into four lobe-like regions from each of which proceeds a fascicle 



