Fig. 121.
Tellina obliqua.
Fig. 122.
Natica helicoides, Johnston.
Among the bones, however, respecting the authenticity of which there seems no doubt, may be mentioned those of the elephant, horse, pig, deer, and the jaws and teeth of field mice ([fig. 141.]). I have seen the tusk of an elephant from Bramerton near Norwich, to which, many serpulæ were attached, showing that it had lain for some time at the bottom of the sea of the Norwich Crag.
At Thorpe, near Aldborough, and at Southwold, in Suffolk, this fluvio-marine formation is well exposed in the sea-cliffs, consisting of sand, shingle, loam, and laminated clay. Some of the strata there bear the marks of tranquil deposition, and in one section a thickness of 40 feet is sometimes exposed to view. Some of the lamellibranchiate shells have both valves united, although mixed with land and freshwater testacea, and with the bones and teeth of elephant, rhinoceros, horse, and deer. Captain Alexander, with whom I examined these strata in 1835, showed me a bed rich in marine shells, in which he had found a large specimen of the Fusus striatus, filled with sand, and in the interior of which was the tooth of a horse.