246 FRESHWATER RHIZOPODS OF NORTH AMERICA. 



The individual of fig. 2, obtained at the same time with the preceding, 

 was composed of homogeneous, finely granular, and colorless protoplasm, 

 with fine yellowish granules intermingled. As food, it contained a diatom 

 and a few brown balls, of which two were afterward seen to be discharged. 

 It also contained a number of clear globules, of which the largest one was 

 observed to collapse, though it did not reappear in the manner of a con- 

 tractile vesicle. Pseudopods projected mainly from one hemisphere, and 

 the animal slowly moved in that direction at the rate of about one millimetre 

 in nine minutes. The creature, on coming into contact with a Closterium, 

 gradually changed from the globular to a three-sided shape, then became 

 oval, and finally again spherical as it moved away from the alga. 



The individual of fig. 3, also found with the preceding, appeared to 

 have its opposite poles rather abruptly prolonged into several of the coarser 

 pseudopodal rays. It contained some scattered colorless and red-colored 

 corpuscles, together with a large vacuole, which remained unchanged. 



A green Heliozoan, resembling those just described in the changeable 

 form of its body, is represented in fig. 10, pi. XLVI. It was found, witli 

 several others of the kind, in Absecom pond, in the month of May. The 

 body is composed of a basis of soft, colorless, granular protoplasm, with 

 green granules diffused through it, but more abundant centrally, where 

 they appear to obscure the nucleus from view. Several contractile vesicles 

 were observed at the periphery. As first seen, the body was elliptical, with 

 the opposite poles giving off the two strongest pseudopodal rays. A large 

 vacuole, containing a food-ball, was in the act of being withdrawn. The 

 creature afterward assumed a spherical form, and then measured one 

 seventh of a millimetre in diameter. 



Later, an active rotifer came into contact with the Heliozoan, and 

 ceased movement as if paralyzed, but after a moment it recovered and 

 attempted to move away. It was, however, restrained by a protruding 

 hemisphere of clear ectosarc, and in the struggle the Heliozoan appeared to 

 be extended toward its victim, and the rays of the same side converged to 

 it. Finally, the rotifer succeeded in making its escape. The portion of 

 clear protruded protoplasm projected several rays, and was then slowly 

 withdrawn, and gradually the Heliozoan assumed once more a spheroidal 

 shape. 



A small colorless Heliozoan, represented in fig. 4, pi. XLV, probably 



