1902.] NATURAL SCIEXCES OF PHILADELPHIA. 257 



the figure. lu the oue case, the processes were stiff, straight and 

 motiouless; iu the other, they exhibited hashing inovemeuts, each 

 separate process acting iudepeudeutly of the others of the same 

 cluster. These two conditions passed readily the one into the 

 other, the processes of a given cluster being at one moment 

 motionless and the next in motion. In the figure, these two con- 

 ditions are shown as occurring alternately, but this division is purely 

 arbitrary. 



In addition to these two, a third condition was observed. At 

 frequent intervals the processes of a number of clusters became 

 animated by a common impulse and exhibited a ciliary movement. 

 All the processes of perhaps one hemisphere of the protozoan lashed 

 or beat vigorously in the same direction, causing a rapid rotation of 

 the body and a progression from one place to another. This 

 phenomenon was seen a number of times, and in each case the 

 activity appeared to involve the processes of only one side of the 

 body at once. It was impossible, however, to determine whether or 

 not this was always the same side. 



The presence within this animal of a partly digested diatom 

 seems to warrant regarding it as belonging to the Rhizopoda 

 (Sarcodina). The spherical form and alveolar protoplasm furnish 

 reasons for considering it a heliozoau. Of the several genera of 

 fresh-water Heliozoa, it comes closest to Actinophrys. The signifi- 

 cation of the curious phenomena observed is problematical, but the 

 observation appears to be worthy of record in that it shows the 

 readiness with which pseudopodia and flagella may change into each 

 other. 



Mr. G. B. Bouleuger, of Loudon, was elected a correspondent. 



The following were ordered to be printed : 



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