| Date Note | From Murchison's trips to Russia in the early 1840s |
| Description | Watercolour of a dermal plate, with monochrome drawing of magnified detail of surface texture, of the fossil fish Psammosteus meandrinus Agassiz, probably by Josseph Dinkel, [1840-1845]. Found in Ladoga, Russia, from the collection of Roderick Murchison. |