66 



DESCRIPTION OF FIGURES. 

 Plate I, 



Fig. 1. Adult Gonionema in resting attitude; floating after 

 a period of active sv/iroming. 2/l. 



" 2. f'edusa in act of swimrning; bell contracted, tenta- 

 cles drawn up at the end of a forward impulse. Pho- 

 tograph from life. l/l. 



3. One radial canal from ripe male, shovfing gonad, 

 c. circular canal; r, radial canal. 8/1. 



" 4. Gonad of female, during dehiscence. 20/l. 

 " 5, Egg during first segmentation; cleavage fui-row half 

 completed. n, nuclei. 1370/l, 



" 6. Egg during second segmentation, left hemisphere 



completely divided, right hemisphere in process of 

 dividing. 



" 7. Hollow blastula 7 hours after fertilization. Opti- 

 cal section of live egg. 



