158 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.57. 



Plate 21. 



Fig. 1-7. Various stages in the progress of the same individual as shown in the 

 previous plate. Figure 1 in a subspherical mass apparently about to 

 di\dde. In figures 2 and 3 the mass flattened out somewhat and with- 

 drew the numerous pseudopodia which had been sent out at the left in 

 figure 1. In figure 4 the fine pseudopodia in the rear had been entirely 

 withdrawn, and in figure 5 those in front had been largely drawn in, leav- 

 ing the mass quiescent for a short period. There is apparently a small 

 nuclear mass in the forward clear part. In figure 6 lines of pseudopodia 

 are again thrust forward, and in figure 7 motion begins again, a tongue 

 of translucent protoplasm being sent forward and a few fine threads being 

 left at the rear as the mass progresses. 



