460 



RA 1)1 ATA : 



FIG. 691. 



iner thej lay their eggs ; and in the autumn they per- 

 ish. 



At length the eggs hatch, and the little planulce, as the 

 newly-hatched Jelly-fishes are called, swim about in the 

 water by means of little appendages calle/,1 vibratile cilia. 



Soon each becomes attached to a rock, shell, or sea- 

 weed, and is then called Scyphistownct 

 (Fig. 691). 



Then the body begins to divide by 

 horizontal constrictions, and soon ap- 

 pears as in Figs. 692, 693, and is then Scyphistoma oiA . flavi . 

 called Strobila. 



At length the segments become more 

 and more separated, and the upper- 

 most one drops off ; then the next one ; then the next, 

 and so on, till each in turn has separated from the one be- 

 low itself. 



dula, Per. and LeS. 



Magnified about seven 



diameters. 



FIG. 692. 



FIG. 693. 



Strobila of A. flavidula, Per. 

 and LeS. Magnified about 

 seven diameters. 



Strobila of A. flavidula, Per. and LeS. Mag- 

 nified fifteen diameters. 



Each disk, as it separates, turns over and floats away, 

 and is known as Ephyra. 



Soon each Ephyra assumes the form of a perfect Jelly- 

 fish, as shown in Fig. 690. 



