In the "Book of Aneirin", a poem entitled " "Peis Dinogat" " (possibly set in the Lake District of Cumbria), contains a usage of the word "penn" "head" (attached to the names of several animals hunted by the protagonist), that is unique in medieval Welsh literature and may, according to Koch, reflect Cumbric influence ("eferring to a single animal in this way is otherwise found only in Breton, and we have no evidence that the construction ever had any currency in the present-day Wales"). The relevant lines are: