[Cnidaria] RE another jelly to identify

[Peter.Schuchert at ville-ge.ch]

> Please, take a look at another jellyfish from the Baltic Sea waiting
> for identification.
> It is a juvenile, about 2 mm in diameter.

its a juvenile Hydractinia medusa (or Podocoryna if you accept the genus).
Juvenile medusae of this family are not identifiable, but it's most likely
H. carnea or less likely H. borealis (see
http://www.ville-ge.ch/mhng/hydrozoa/pdf/schuchert2008a.pdf).

Do you have living specimens?

regards,
Peter