EDMONDSON — PROTOZOA OP IOWA. 71 



In all forms observed in the state but two nuclei were present, 

 they being widely separated. Smith, of New Orleans, also reports 

 that the species of his locality possesses but two nuclei. Careful 

 staining has failed to reveal the racemose system of nuclei as 

 demonstrated by Wrzesniowski. It may be that the species varies 

 somewhat in this particular. 



Found in the bottom of old infusions of pond water. Movement, 

 a gliding motion. 



TRACHEIvIUS Ehrenberg. 



Oval or elongate, elastic. Oral aperture at the base of a short 

 flexible neck-like extension of the anterior extremity. 



Trachelius ovum Hhr. 



Body oval or nearly spherical, broadly rounded posteriorly, 

 produced anteriorly into a narrow, short, but highly flexible 

 neck-like prolongation. Oral aperture circular, leading into a 

 short, longitudinally striated pharynx. Nucleus central. Con- 

 tractile vesicles numerous. 



IvCngth, 300 microns. (Fig. no, PI. XIV.) 



The body of this species usually presents a highly vacuolated 

 appearance. From the inner end of the pharynx the endoplasm 

 spreads out into four or five broadly diverging ramifications. The 

 nucleus is band-like or oval and sometimes two independent 

 nuclei may be seen. 



Found in fresh water but not abundant. Reproduction by 

 transverse division. 



Family, CHEAMYDODONTID^. 



NASSUEA Ehrenberg. 



Body ovate, cylindrical. Mouth lateral. Pharjnix a cylindrical 

 tube, with or without rod-like teeth, usually dilated at the 

 exterior end. Nucleus spherical. Contractile vesicles sometimes 

 multiple. Trichocysts often present. Body brightly colored. 



Nassula oronata Ehr. 



Body elongated, oval or elliptical, cylindrical. Pharyngeal 

 tube composed of a number of rod-like teeth dilated at the exterior 

 end. Nucleus large, spherical, posteriori 5^ located. Contractile 

 vesicle single. Usually some shade of red or brown in color. 



