NANOMIA. 81 



living beings is most graceful. The oil bubble (Fig. 116) at the 

 upper end is their float ; the swimming bells immediately below 

 it (Fig. 110), by the convulsive contractions of which they move 

 along, are their oars. The water is not taken in and expelled 



again by all the bells at once, but first from all the bells on 

 one side, beginning at the lower one, and then from all those on 

 the opposite side, beginning also at the lower one ; this alter- 



Fig. 115. Adult Nanomia, natural size, at rest. 

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