on Mammalian Remains in the Crag. 225 



under the waters during the diluvial clay epoch ; but I cer- 

 tainly do not suppose, that the Mammalia and crag mollusks 

 were contemporaneous, though their remains are occasionally 

 found together. In this point we both meet. The explana- 

 tion thus brought out will do no harm, — it enables facts to be 

 quoted, which might have remained unnoticed. As to the oc- 

 currence of bones of land animals in other lower supra-creta- 

 ceous deposits, they also might fall under the head of drift. 

 At Walton Naze, 800 or 900 yards from the village, and se- 

 veral rods from the shore, there was found an elephant's tusk, 

 8 feet in length ; the chord of the arc was 7 ft. 3 in., and the 

 circumference was, at the largest end, 18 inches. It was found 

 in the London clay, sticking upright, just above the low wa- 

 ter level. It was evidently a drift tusk, and had probably 

 been washed from above, at an ancient period, and exposed 

 from the effects of denudation, by the wear of the sea on that 

 ruinous coast. Bones similar to those I have mentioned from 

 the crag at Walton, have been also found in true surface-drift 

 near Flatford Bridge, in East Bergholt ; and a bone of great 

 size was taken thence in 1829, and when I left Suffolk in 1831, 

 was, I think, in the possession of Abram Constable, Esq. of 

 Flatford Mill. That the the crag was not upheaved till after 

 the irruption of the drift or diluvium of Suffolk and Norfolk, 

 I hope I have sufficiently established in the paper I before 

 alluded to ; admit this, and there can be no difficulty as to 

 the question, how the remains of land animals of the diluvial 

 epoch may have been drifted upon or into the crag, or Lon- 

 don clay, before the upheaving of the crag occurred ; for I 

 imagine that causes similar to those now in action, were in be- 

 ing both before and after the great convulsion which covered 

 parts of East Anglia with from 300 to 400 feet of drift clay 

 and gravel ; — and that land floods and rivers bore down, as 

 now, to the sea, whatever they found capable of transportation. 

 My knowledge of the conchological history of the crag is 

 very limited, and on this point I must confess your acquire- 

 ments such as to make you an authority which I ought not to 

 dispute. Yet so far as the superficial Geology of Suffolk goes, 

 I venture to suppose you will allow I have a claim to offer an 

 opinion ; and I think we do not differ therein. 



Stanley Green, Yours faithfully, 



March 1st, 1838. W. B. Clarke. 



Editor of the Magazine 



of Natural History. 



T 2 



