1662 J. Chandler tr. J. B. van Helmont lvi. 419 The Ileon is extended, perhaps for 40 turns, as well from the back forwards, as with a side passage on both sides.
1831 W. Scott Count Robert iii, in 4th Ser. I. 81 Side passages opened into it.
2014 R. W. Brucker & R. A. Watson in C. Burns & K. Burns 130 Phil explored a side passage while Bill went on down the main canyon.