20 DAVENPORT ACADEMY OF SCIENCES. 



The pseudopodia are transparent, variable in length, sharp 

 pointed and may be branched or not but do not anastomose. A 

 large sphericle nucleus is present but usually not visible without 

 the aid of reagents. 



Sometimes found in great abundance in pond water among dia- 

 toms, upon which it feeds. 



Cochliopodhim vestituvi, differing from the above species chiefly 

 in the shell being covered with rigid cilia and in the green color 

 of the endoplasm, probably also appears in this state but has not 

 so far been observed. 



PAMPHAGUS Bailey. 



Body enclosed within a transparent, elastic membrane. Endo- 

 plasm completely filling the membrane, more or less granular. 

 Mouth small, terminal. Pseudopodia long, delicate, branching 

 but not anastomosing. 



Pamphagus mutabilis Bailey. 



Body ovoid in shape, seldom changing form, the oral extremity 

 more acutely rounded than the fundus. Mouth small, often indi- 

 cated only by the region from which the long, delicate pseudo- 

 podia are extended. Nucleus large, spherical. 



Length, 60 microns. (Fig. 32, PI. V.) 



This organism is not common in the waters of this state, but 

 it is very active, usually being found with its long, branching 

 pseudopodia widely extended. 



The closely investing covering of the body prevents any great 

 distortion, although slight changes of form sometimes occur. As 

 a result of stimuli the organism withdraws its pseudopodia and 

 assumes a rounded or spherical form. 



Pamp/m^us, no doubt, represents a development of Amceba to 

 such an extent that the ectoplasm has become differentiated to 

 form a resisting membrane. The plate figure represents an indi- 

 vidual taken from a running stream near Iowa City in December, 

 1905. Found in the ooze at the bottom of ponds, rivers and lakes. 



Family, EUGLYPHID^. 

 CYPHODERIA Schlumberger. 



Shell composed of chitinous material, curved backward from 

 the mouth, retort-shaped. Pseudopodia delicate and branching. 



