496 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [May 25, 
but in their place large flints, a few bits of hardened clay, and bones 
and teeth of Cervus*, Hquus, and also Trogontherium. Further, it is to 
be remarked that the teeth of Mastodon found in the Norfolk stone- 
bed are not so thoroughly mineralized and so heavy as those from 
the Suffolk bone-bed, whilst the bones which occur in that bed are 
certainly by no means so heavy as those from Suffolk. The Norfolk 
stone-bed rests on chalk, the Suffolk bone-bed on London clay. 
Immediately above the Norfolk stone-bed is the Norfolk Crag, with 
_ its nearly recent subarctic molluscan fauna. Immediately above 
the Suffolk bone-bed is the Coralline Crag with its many extinct and 
tropical forms, or, where this is not present, the lower and older 
part of the Red Crag, or, in some places, higher sandy beds. Both 
stone-bed and bone-bed have, in places, been much disturbed and 
broken up by the sea which deposited the strata above them. Tak- 
ing these facts into consideration, it is impossible to assign a simple 
community of origin and date to these two beds. The Suffolk bone- 
bed has evidently derived its contents from sources which were not . 
accessible to the Norfolk deposit ; sueh are the London clay and the 
destroyed Diestien beds. But what of the terrestrial Mammalia 7 ? 
Was the Mastodon of the Norfolk stone-bed coeval with the Masto- 
don of the Suffolk bone-bed? If it were, we must suppose that the 
Rhinoceros Schleiermacheri, Hipparion, &c. of the Suffolk bed belong 
to an earlier age, and were not contemporary with the Mastodon 
arvernensis found with them, since in the Norfolk area these other 
forms are not present with the Mastodon. Also we must assume 
that the Hlephas meridionalis, Equus, and Trogontherium of the 
Norfolk stone-bed belong to a later period than the Mastodon 
arvernensis found with them, since it may be positively asserted that 
Elephas does not occur in the Suffolk bone-bed. Again, there is no 
doubt that the terrestrial mammalian fauna (not considering here 
the well-identified Hocene species of Coryphodon and Hyracotherium 
which occur) of the Suffolk bone-bed is earlier in date than the 
Coralline Crag, and, perhaps, earlier than the Diestien beds which 
preceded that Crag, since I have obtained the tooth of a Trilophodont 
Mastodon from the bone-bed, with the Diestien sandstone-matrix 
enveloping it. This cannot be said of the Mammals occurring at 
the base of the Norwich Crag. All that we can assert of them is 
that they belong to an earlier date than the newer Crag; they are 
possibly not so old as the Coralline or even the earlier part of the 
Red Crag. The condition of the Mastodon teeth from the Norfolk 
stone-bed is decidedly one of less mineralization than that of 
those from the Suffolk bed, and none of them bear marks of the same 
extensive water-wearage which are apparent on very many from 
Suffolk. Moreover, the Rev. John Gunn obtained very fair evidence 
of the occurrence of a nearly complete skeleton of Mastodon arver- 
* Mr. Boyd Dawkins, F.R.S., considers that there are species of Cervus com- 
mon to the Suffolk bone-bed and the Norfolk stone-bed. 
+ In using the term “ terrestrial mammalia of the Suffolk bone-bed ” I wish 
to be understood as excluding the derived Eocene. Coryphodonts and Hyraco- 
therium. ‘These, however, are the only Hocene forms which have occurred. 
