6o '. DAVENPORT ACADEMY OF SCIENCES. 



HOLOPHRYA Ehrenberg. 



Ovate or elongate, changeable in form. Oral opening in anterior 

 border, terminal. Cilia of entire body of uniform size. 



HoLOPHRYA KESSLERii Meresch. 



Body elongate, cylindrical, posterior border rounded, anterior 

 border truncate. Surface furrowed longitudinally. Nucleus 

 elongate, band-like, centrally located. Contractile vesicle posterior. 

 Length when extended, 125 microns. (Fig. 89, PI. XII.) 

 A rare form in this state. It has been found in fresh water in 

 Johnson county among algae. Solitary in its habits. Movement 

 rapid, by turning on its longitudinal axis. On contraction the 

 longitudinal striations do not become oblique as in case of //o/o- 

 phrya tarda, a closely allied form. 



UROTRICHA C. & L. 



Oval or elliptical. Cilia not moving in unison. Oral aperture 

 at the anterior extremity, terminal. A long seta used as a spring- 

 ing hair, developed from the posterior extremity. Contractile 

 vesicle and nucleus usually conspicuous. 



Urotricha pi,atystoma Stokes. 



Body ovate, a little longer than broad, equally rounded at both 

 extremities. Cilia covering the entire body, vibrating independ- 

 ently. Surface covered with minute, round, bead-like elevations 

 arranged in longitudidal series. Mouth capable of very wide 

 expansion. Springing hair shorter than the body, pointing 

 obliquely, with the distal end curved. 



Length of body, 40 microns. (Fig. 90, PI. XII.) 



Urotricha platy stoma reproduces by transverse division. Move- 

 ment is by rotation on its longitudinal axis, frequently darting to 

 one side by means of the posterior springing hair, not unlike 

 Halteria . 



The form has often been found in fresh water in this state. 



Urotricha sp. 



Body ovate, wider anteriorly, more acutely rounded posteriorly. 

 Surface smooth. Movement 6f cilia very irregular and independ- 

 ent. Oral aperture apical, terminal, provided with two lip-like 

 extensions of unequal length. Springing hair short, less than 



