THE HYDRA AND ITS ALLIES 



213 



beautiful inhabitants of the sea. Those who have crossed 

 the Atlantic are acquainted with the " Portuguese man-of- 



FIQ. 2QO. Physalia arethusa. 

 Nat. size. After Agassiz. 



ntc 



FIG. 201. Hahstemma tergt- 

 stinutn. The entire colony. 

 coe, cosnosarc; dz, dactyle- 

 zooid ; hph, hydrophyllium or 

 bract; net, nectocalyx or swimming-bell ; ntc, battery of nematocysts; 

 p, polyp; pn, pneumatophore or float; t, tentacle. After Glaus. 



