EDMONDSON — PROTOZOA OF IOWA. 97 



Ventral surface covered with fine cilia arranged in longitudinal 

 rows. Peristome triangular. Nuclei usually more than one. Con- 

 tractile vesicle single. 



Urostyla grandis Ehr. 



Body rounded at each extremity, narrower anteriorly. Peris- 

 tome triangular, reaching backward nearly one-third the length 

 of the body, the posterior angle curved. Frontal styles numerous, 

 scattered. Ten or twelve slender anal styles; ventral rows of cilia 

 numerous. Marginal series of .setae complete. Nuclei usually 

 two. Contractile vesicle on the left side anterior to the middle. 



Length, 250-400 microns. (Fig. 159, PI. XXII.) 



Found in fresh water. The forms observed in this state pos- 

 sessed two nuclei each with a distinct micronucleus attached. 



The endoplasm often presents a yellowish appearance due, prob- 

 ably, to the ingested diatoms and other unicellular plants upon 

 which the organism ravenously feeds. 



STICHOTRICHA Perty. 



Wider posteriorly, anterior region slender, neck-like and very 

 flexible. Peristome, a furrow leading backward to the middle of 

 the body and ending in the mouth. Frontal styles sometimes 

 wanting, one or more oblique rows of large ventral setae, no anal 

 styles. Marginal setae forming a complete border. 



Anterior half of the body often with very long, slender, hair- 

 like setae. Animal sometimes inhabiting a lorica. 



STICHOTRICHA ACULEATA Wrzes. 



Body with posterior extremity bluntly pointed. Two prom- 

 inent styles extending from the anterior border, ventral setae in 

 two oblique rows. The anterior body-half bordered by two 

 opposite rows of very slender hair-like setae. 



Oral furrow bordered with long, fine cilia. Nuclei two, cen- 

 trally located. Contractile vesicle posterior to the mouth. 



Length, 120 microns. (Fig. 171, PI. XXIV.) 



This species has been obtained from fresh water in Cedar 

 county, but is not a common form in this state. It has not been 

 found inhabiting a lorica or sheath of any kind, but has always 

 been observed as a free-swimming organism. 



[Proc. D. a. S., Vol. XI.] 13 [June 8, 1906.! 



