Chonella tenuis
Roemer 1864
Chonella tenuis is quite rare at Misburg and Höver. It is a thin-walled (4-6 mm) ear-shaped or plate-like sponge, which may easily be confused with a Verruculina or with Procorallistes polymorphus.
However, Chonella tenuis does not possess the papilliform, protruding postica characteristic of Verruculina, and Procorallistes tends to be more thick-walled and has a different spiculation, including dermal dichotriaenes (if preserved).
The typical specimen of Chonella tenuis shown here from both sides displays nicely the rim-less, pinhole-sized pores, some concentric growth lines, and the rounded margin.
None of the Chonella specimens known to the author have roots. Apparently Chonella is always attached to other sponges.
A larger and composite specimen of Chonella tenuis.