Colony of Dynamena pumila (Linnaeus, 1758) (Leptomedusae, Sertulariidae), ca. 5 cm, Dunstaffnage, Scotland. In the upper part some hydranths can be seen, note also the presence of gonothecae (oval bodies on stem).  The author has granted permission to MarBEF/VLIZ to use this picture in ERMS and related biological databases hosted at VLIZ.  Source: http://www.ville-ge.ch/musinfo/mhng/hydrozoa/hydrozoa-directory.htm