Microblastidium decurrens
Schrammen, 1902
Previously, Microblastidium decurrens has been reported only from Oberg (near Ilsede, 50 km east of Hannover), as a rare species (Schrammen, 1902, 1912). Complete specimens are not yet known.
The two specimens shown here are fragments of the upper parts of the sponge. They show an obconical habit with pronounced longitudinal furrows and ribs. The latter consist of aligned conical protrusions with up to several pores (ostia ?).