The lower mandible of a chimæra—the first discovered in the Lower Greensand—is now in the collection of Sir Philip Egerton, who informs me it belongs to the species Ischyodus Agassizii. Since this discovery I have met with many more specimens, some of smaller size; but, from the difficulty of extracting them from the stone, I have never succeeded in getting one so perfect. Several good specimens have been procured from the Lower Chalk at Burham. The chimæra approaches in form to the shark tribe, but it is far from being so ravenous in its disposition. Recent species are found in the Arctic and in some of the European seas, and attaining the length of two or three feet. Being often taken in the company of the herrings in their migrations, it has thus gained the patronymic of “king of the herrings.” The mouth of this odd-looking fish is furnished with hard and undivided plates instead of teeth, four of which are placed on the upper and two on the lower jaw.

Fossils are very rare in the succeeding “rugged flint layers,” which have an average thickness of eight inches.