Note 62 — PART III.

As might be expected, vertebrate remains occur chiefly in the sandy and clayey beds. Skeletons of marine animals such as Zeuglodon and Eosiren may, however, be frequently observed embedded in the hard intercalated limestones. Limestone cranial-casts of these animals are thus sometimes found, and one of these has already been figured and described (Elliot Smith, The Brain of the Archæoceti, Proceedings Royal Society, Vol. 71, pp. 322-331. Some most beautifully formed casts from one of the limestone beds were eventually determined by Andrews to be casts of the air passages of crocodile skulls.