Kalpinella pateraeformis
Hinde 1883
Kalpinella species have not been reported before from Northern Germany. Hinde (1883) described the species from the Upper Green Sand of Warminster, England.
Kalpinella pateraeformis occurs as shallow and expanded cup- or funnel-shaped sponges, exceeding 110 mm diameter. It may have a stem, or may occur sessile. The upper and under surfaces of the sponge carry many, fairly large (1-1.5 mm) pores.
The skeleton is composed of smooth tetraclones, united via zygomes.
The specimen in the two pictures is fairly large and quite flat. The wall is slightly more than 10 mm thick and attenuates towards the center. At the bottom there are a few small (10 mm) wart-like roots. The specimen is attached to a piece of sponge which served as an initial substrate. The rim of the sponge is rounded and shows many radial grooves.