I02 DAVENPORT ACADEMY OF SCIENCES. 



Stylonychia sp. 



Figure 170, Plate XXIII, represents a species of this genus 

 found commonly among algae in the fresh waters of Johnson 

 county. So far as I have been able to determine the form does 

 not correspond with any described species. Conn, in a recent 

 report entitled "The Protozoa of the Fresh Waters of Connecti- 

 cut," Fig. 267, PI. 29, illustrates a species of Stylonychia which 

 apparently corresponds very closely to the Iowa form as described 

 below and may be identical with it. 



Body elongate -oval, wider anteriorly, rounded posteriorly. 

 Right-hand border convex, left-hand more or less concave, giving 

 the body a bent appearance. Two of the anal styles extending 

 beyond the posterior border. Caudal setae exceedingly long and 

 flexible. 



Endoplasm often partially or completely filled with green chro- 

 matophores. 



Length, 200-300 microns. 



Stylonychia pustulata Ehr. 



Body oval, about twice as long as broad, rounded at each ex- 

 tremity. Caudal setae short. Nuclei two. Contractile vesicle 

 single. 



Length, 150-170 microns. (Fig. 162, PI. XXIL) 



This species is usually common in infusions of stagnant water, 

 often developing in great numbers. Reproduction takes place 

 rapidly by transverse fission. Movement, as in other members of 

 the family, is a quick, jerky motion. 



Distribution over the state is general. 



Stylonychia notophora Stokes. 



Body elongate-elliptical, rounded posteriorly, the front margin 

 obliquely truncate on the left side, rounded or slightly concave on 

 the right side. Five scattered ventral styles; three anal styles 

 project beyond the posterior border. Caudal setae long and widely 

 separated, having their origin on the dorsal surface near the pos- 

 terior margin. Peristome extending nearly to the middle of the 

 bod)', the left-hand border with an undulating membrane. Nuclei 

 two in number. Contractile vesicle single, on the left side, on a 

 level with the posterior angle of the peristome. 



