3 6 /;/ vertebral a. 



each appears somewhat umbrella-shaped, and the 

 margin of its disk or swimming bell is adorned with 



FIG. 2t. 



Different stages of Meduspids : A, rooted hydroid colony, natural size ; B, 

 polypite magnified, showing tentacles and reproductive polypites in five 

 successive stages of development ; c, D, reproductive medusoids, detached, 

 showing the marginal tentacles, the eyes, and the veil. 



little, naked, coloured specks supposed to be eye 5 :, 

 and also with marginal tentacles. A central mouth 

 exists on the under side of the swimming bell, opening 



