212 FRESH- WATER RHIZOPODS OF NORTH AMERICA. 



frequent in the superficial ooze of ponds, ditches, and lakes, and in such 

 positions I have observed them in all parts of the country mentioned in 

 other pages of this work. 



Not unfrequently Euglypha alveolata is found with the sarcode con- 

 tracted and in various stages of encystment, as represented in figs. 9, 10, 

 14, pi. XXXV. Usually in these the mouth of the shell is closed with an 

 epiphragm, often more or less laminated in appearance, and composed of 

 materials discharged from the sarcode mass as it was about to assume the 

 encysted condition. 



In one of the specimens observed, represented in fig. 9, the encysted 

 sarcode mass formed an egg-like body covered with a shell having the same 

 structure as that of the parent shell enclosing it. The sarcode itself was 

 pale yellowish, of uniform granular constitution, mingled with fine oil 

 molecules. 



In other specimens, as seen in figs. 10, 14, the sarcode mass within 

 the egg-shaped shell was contracted into a nearly spherical ball, and was 

 invested with a distinct homogeneous membrane. The sarcode, in some 

 such specimens, was finely granular, and in others was mingled with numer- 

 ous oil-like globules. 



Living active individuals of Euglypha alveolata are frequently to be met, 

 containing in the sarcode, in a zone around the position of the nucleus, a 

 multitude of rods, as seen in fig. 1. These rod-like bodies are likewise 

 often seen occupying nearly the same position, but often irregularly scat- 

 tered, in dead shells, and in these they are recognizable as detached plates, 

 like those composing the shell of the Euglypha. What the meaning of this 

 condition is I have been unable to determine. I have conjectured that it 

 might be due to the hatching of an ovum-like body, such as those above 

 described, and the retention of the plates of its broken-up shell within 

 that of the parent. 



On one occasion I observed a pair of specimens of Euglypha alveolata 

 in a peculiarly interesting condition, which led me to believe that I had 

 found the animal in the process of reproduction. As first seen, when the 

 specimens attracted my attention, they exhibited the appearance repre- 

 sented in fig. 15. One of the individuals, which may, for convenience, be 

 called the parent, had the usual form, and was -Jth mm. long. It had 

 eight points to the mouth, and four long spines to the fundus, somewhat 



