EDMONDSON — PROTOZOA OF IOWA. 23 



Trme?na enchelys is one of the smallest and most abundant of 

 fresh water Rhizopods. Its distribution is wide, being found in 

 man}- localities of this state. It is commonly found in the ooze 

 at the bottom of ponds and among diatoms and algse. 



Sub-class, HELIOZOA. 

 Order, APHROTHORACIDA. 



ACTINOPHRYS Khrenberg. 



Body a spherical mass of granular protoplasm from which radi- 

 ate delicate, tapering, ray-like pseudopodia. Nucleus and con- 

 tractile vesicles conspicuous. 



ACTINOPHRYS SOI. Ehr. 



Body of granular protoplasm, without chlorophyl. Diameter 

 of body, 100 microns. (Fig. 36, PI. V.) 



The normal appearance of Adinophrys sol as it rests in the 

 water is a spherical mass of highly vesicular protoplasm with its 

 ray-like pseudopodia in an active state of extension and retraction. 



Among the many vesicles one or more are contractile. Before 

 bursting the contractile vesicle or vesicles rise to the surface, 

 push out the periphery as large, semi-spherical, transparent, glob- 

 ules and then suddenly collapse. 



The nucleus is large, spherical, central in position and may or 

 may not be visible without the aid of reagents. 



Reproduction may frequently be seen to take place by simple 

 fission, a constrictibn of the body mass occurring and the two 

 portions drawing apart. 



The species has been found in great abundance in spring water 

 in the vicinity of Iowa City, but also may be found in more stag- 

 nant pond water. 



Its distribution is very general. 



ACTINOPHRYS PicTA Eeidy. 



Protoplasm of body as in Adinophrys sol, but bright green in 

 color due to the presence of chlorophyl. Diameter of body approx- 

 imately that of Adinophrys sol. 



Many forms of the above description have been found in spring 

 water near Iowa City associated with Adinophrys sol. In size and 



