hydr-

There are at least three well-marked species of hydræ to be met with in the ponds and ditches of this country.

They are something like the hydræ in their power of producing lost portions of their bodies.

Polypifera, including the Hydræ, Sertularia, and Pennatulariæ.

The tentacles attached to this set of Hydræ are exceedingly long and delicate.

But as this latter star is now known to be irregularly variable it seems probable that α Hydræ may be variable also.