Serpula sulcata (J.de C. Sowerby) on Gryphaea (Bilobissa) dilatata (Sowerby).
The lover valve of a type of Jurassic oyster. On one surface are a number of well preserved marine worms which have cemented themselves the hard substrate of the oyster shell on which to grow and live.
Jurassic, Oxford Clay.
Stanton Harcourt, Oxfordshire.
Specimen : 9 x 7.5 x 1.3 cm.
