Mention is made of this slab by Mr. E. Etheridge, jun., in his Presidential Address to the Royal Physical Society of Edinburgh, p. 50. The specimen is in the Museum of Natural History, Cromwell Eoad, South Kensington.

The slab shows a piece of fossil wood 2¾ in. long by about 1½ in. broad, the exact nature of which is not determinable on account of its bad state of preservation, but this is fortunately not germane to the subject; it lies flat and compressed and is surrounded on three sides by masses of Mollusca, in places two and three deep, which have doubtless been attached to the wood by their byssi. The anterior ends and in many cases the inferior borders are turned towards the piece of wood and are in close contact with it, while others are again attached to the first row, as in masses of living mussels.