This very old specimen has great historic appeal, dating from the Tunnel dig in the late 1800s and early 1900s. It is sharply twinned, resulting in the unusual habit here. These are THE CLASSICS for the species, but so few were found an dpreserved, and they are mostly in museums. This sharp, large thumbnail is a rarified and highly difficult to obtain specimen. For more on the location see " How the Swiss Built the Greatest Tunnel in the World, 1905": http://www.fordham.edu/HALSALL/mod/1905simplon.html