HYDROZOA. 



81 



Class 

 HYDKOZOA. 



No umbrella. 



An umbrella. 



r 



An hydrorliiza. 



No hydrorhiza. 

 Oceanic. 



^ 



Locomotive. 

 Inhabiting fresh-water. 



Order I. 

 Hydeidje. 



Fixed. 



No hydrothecse. 

 Order II. 



CoRYXIDiE. 



Hydrothecse. 



Order III. 

 Sebtularid^. 



"~\ 



Polypites free from nectocalyces. 



Polypite sus- 

 pended from 

 the roof of a 

 nectocalyx. 



No pneumatophore. A pneumatophore. 

 Nectocalyces. Nectocalyces 



A Somatocyst. present or absent. 



Order IV. 

 Calycophoridje. 



Order V. 

 Physopsorid^. 



Order VI. 

 Medusid^. 



^ 



Order VII. 



LUCERNARID^. 



