Siphonia

Siphonia is a genus of extinct hallirhoid demosponges of the Lower and Upper Cretaceous, from about 125 to 66 million years ago. They lived in the Western Tethys Ocean, in what is now Europe.

Description
They all had distinctive pear-shaped bodies that were attached to the seafloor via a long stem. Their common name, "tulip sponges," refers to their suggestive shape, while the genus name refers to how the spongocoel (the main tube of the sponge body) runs almost the entire length of the sponge, as though it were almost a drinking straw.