https://books.google.it/books?id=MdytpHTVf1gC&pg=PA301&lpg=PA301&dq=proteus+catoptricus&source=bl&ots=RSX10ocFje&sig=HG-kGEh7wcZMd86yyjQ6x2ZzgOM&hl=it&sa=X&ved=0ahUKEwiiyL259YLSAhXD1RQKHT1_AS8Q6AEIHzAA#v=onepage&q=proteus%20catoptricus&f=false
